Lost: Season One
Along with Desperate Housewives, Lost was one of the two breakout shows of 2004. Mixing suspense and action with a sci-fi twist, it began with a thrilling pilot episode in which a jetliner traveling from Australia to Los Angeles crashes, leaving 48 survivors on an unidentified island with no sign of civilisation or hope of imminent rescue. That may sound like Gilligan's Island meets Survivor, but Lost kept viewers tuning in every Wednesday night--and spending the rest of the week speculating on Web sites--with some irresistible hooks (not to mention the beautiful women). First, there's a huge ensemble cast of no fewer than 14 regular characters, and each episode fills in some of the back story on one of them. There's a doctor; an Iraqi soldier; a has-been rock star; a fugitive from justice; a self-absorbed young woman and her brother; a lottery winner; a father and son; a Korean couple; a pregnant woman; and others. Second, there's a host of unanswered questions: What is the mysterious beast that lurks in the jungle? Why do polar bears and wild boars live there? Why has a woman been transmitting an SOS message in French from somewhere on the island for the last 16 years? Why do impossible wishes seem to come true? Are they really on a physical island, or somewhere else? What is the significance of the recurring set of numbers? And will Kate ever give up her bad-boy fixation and hook up with Jack? Lost did have some hiccups during the first season. Some plot threads were left dangling for weeks, and the "oh, it didn't really happen" card was played too often. But the strong writing and topnotch cast kept the show a cut above most network TV. The best-known actor at the time of the show's debut was Dominic Monaghan, fresh off his stint as Merry the Hobbit in Peter Jackson's Lord of the Rings films. The rest of the cast is either unknowns or "where I have I seen that face before" supporting players, including Matthew Fox and Evangeline Lilly, who are the closest thing to leads. Other standouts include Naveen Andrews, Terry O'Quinn (who's made a nice career out of conspiracy-themed TV shows), Josh Holloway, Jorge Garcia, Yunjin Kim, Maggie Grace, and Emilie de Ravin, but there's really not a weak link in the cast. Co-created by J.J. Abrams (Alias), Lost left enough unanswered questions after its first season to keep viewers riveted for a second season

Lost: Season Two
What was in the Hatch? The cliffhanger from season one of Lost was answered in its opening sequences, only to launch into more questions as the season progressed. That's right: Just when you say "Ohhhhh," there comes another "What?" Thankfully, the show's producers sprinkle answers like tasty morsels throughout the season, ending with a whopper: What caused Oceanic Air Flight 815 to crash in the first place? As the show digs into more revelations about its inhabitant's pasts, it also devotes a good chunk to new characters (Hey, it's an island; you never know who you're going to run into.) First, there are the "Tailies," passengers from the back end of the plane who crashed on the other side of the island. Among them are the wise, God-fearing ex-drug lord Mr. Eko (standout Adewale Akinnuoye-Agbaje); devoted husband Bernard (Sam Anderson); psychiatrist Libby (Cynthia Watros, whose character has more than one hidden link to the other islanders); and ex-cop Ana Lucia (Michelle Rodriguez), by far the most infuriating character on the show, despite how much the writers tried to incur sympathy with her flashback. Then there are the Others, first introduced when they kidnapped Walt (Malcolm David Kelley) at the end of season one. Brutal and calculating, their agenda only became more complex when one of them (played creepily by Michael Emerson) was held hostage in the hatch and, quite handily, plays mind games on everyone's already frayed nerves. The original cast continues to battle their own skeletons, most notably Locke (Terry O'Quinn), Sun (Yunjin Kim) and Michael (Harold Perrineau), whose obsession with finding Walt takes a dangerous turn. The love triangle between Jack (Matthew Fox), Kate (Evangeline Lilly) and Sawyer (Josh Holloway), which had stalled with Sawyer's departure, heats up again in the second half. Despite the bloating cast size (knocked down by a few by season's end) Lost still does what it does best: explores the psyche of people, about whom "my life is an open book" never applies, and cracks into the social dynamics of strangers thrust into Lord of the Flies-esque situations. Is it all a science experiment? A dream? A supernatural pocket in the universe? Likely, any theory will wind up on shaky ground by the season's conclusion. But hey, that's the fun of it. This show was made for DVD, and you can pause and slow-frame to your heart's content. 
Lost: Season Three

When it aired in 2006-07, Lost's third season was split into two, with a hefty break in between. This did nothing to help the already weirdly disparate direction the show was taking (Kate and Sawyer in zoo cages! Locke eating goop in a mud hut!), but when it finally righted its course halfway through--in particular that whopper of a finale--the drama series had left its irked fan base thrilled once again. This doesn't mean, however, that you should skip through the first half of the season to get there, because quite a few questions find answers: what the Others are up to, the impact of turning that fail-safe key, the identity of the eye-patched man from the hatch's video monitor. One of the series' biggest curiosities from the past--how Locke ended up in that wheelchair in the first place--also gets its satisfying due. (The episode, "The Man from Tallahassee," likely was a big contributor to Terry O'Quinn's surprising--but long-deserved--Emmy win that year.) Unfortunately, you do have to sit through a lot of aforementioned nuisances to get there. Season 3 kicks off with Jack (Matthew Fox), Kate (Evangeline Lilly), and Sawyer (Josh Holloway) held captive by the Others; Sayid (Naveen Andrews), Sun (Yunjin Kim), and Jin (Daniel Dae Kim) on a mission to rescue them; and Locke, Mr. Eko (Adewale Akinnuoye-Agbaje), and Desmond (Henry Ian Cusick) in the aftermath of the electromagnetic pulse that blew up the hatch. Spinning the storylines away from base camp alone wouldn't have felt so disjointed were it not for the new characters simultaneously being introduced. First there's Juliet, a mysterious member of the Others whose loyalty constantly comes into question as the season goes on. Played delicately by Elizabeth Mitchell (Gia, ER, Frequency), Juliet is in one turn a cold-blooded killer, by another turn a sympathetic friend; possibly both at once, possibly neither at all. (She's also a terrific, albeit unwitting, threat to the Kate-Sawyer-Jack love triangle, which plays out more definitively this season.) On the other hand, there's the now-infamous Nikki and Paulo (Kiele Sanchez and Rodrigo Santoro), a tagalong couple who were cleverly woven into the previous seasons' key moments but came to bear the brunt of fans' ire toward the show (Sawyer humorously echoed the sentiments by remarking, "Who the hell are you?"). By the end of the season, at least two major characters die, another is told he/she will die within months, major new threats are unveiled, and--as mentioned before--the two-part season finale restores your faith in the series.  

Lost: Season Four
Season four of Lost was a fine return to form for the series, which polarized its audience the year before with its focus on The Others and not enough on our original crash victims. That season's finale introduced a new storytelling device--the flash-forward--that's employed to great effect this time around; by showing who actually got off the island (known as the Oceanic Six), the viewer is able to put to bed some longstanding loose ends. As the finale attests, we see that in the future Jack (Matthew Fox) is broken, bearded, and not sober, while Kate (Evangeline Lilly) is estranged from Jack and with another guy (the identity may surprise you). Four others do make it back to their homes, but as the flash-forwards show, it's definitely not the end of their connection to the island. Back in present day, however, the islanders are visited by the denizens of a so-called rescue ship, who have agendas of their own. While Jack works with the newcomers to try to get off the island, Locke (Terry O'Quinn), with a few followers of his own, forms an uneasy alliance with Ben (Michael Emerson) against the suspicious gang. Some episodes featuring the new characters feel like filler, but the evolution of such characters as Sun and Jin (Yunjin Kim and Daniel Dae Kim) is this season's strength; plus, the love story of Desmond (Henry Ian Cusick) and Penny (Sonya Walger) provides some of the show's emotional highlights. As is the custom with Lost, bullets fly and characters die (while others may or may not have). Moreover, the fate of Michael (Harold Perrineau), last seen traitorously sailing off to civilisation in season two, as well as the flash-forwards of the Oceanic Six, shows you never quite leave the island once you've left. There's a force that pulls them in, and it's a hook that keeps you watching. Season four was a shorter 13 episodes instead of the usual 22 due to the 2008 writers' strike.

Lost: Season Five
Since Lost made its debut as a cult phenomenon in 2004, certain things seemed inconceivable. In its fourth year, some of those things, like a rescue, came to pass. The season ended with Locke (Terry O'Quinn) attempting to persuade the Oceanic Six to return, but he dies before that can happen--or so it appears--and where Jack (Matthew Fox) used to lead, Ben (Emmy nominee Michael Emerson) now takes the reins and convinces the survivors to fulfill Locke's wish. As producers Damon Lindelof and Carlton Cuse state in their commentary on the fifth-season premiere, "We're doing time travel this year," and the pile-up of flashbacks and flash-forwards will make even the most dedicated fan dizzy. Ben, Jack, Hurley (Jorge Garcia), Sayid (Naveen Andrews), Sun (Yunjin Kim), and Kate (Evangeline Lilly) arrive to find that Sawyer (Josh Holloway) and Juliet (Elizabeth Mitchell) have been part of the Dharma Initiative for three years. The writers also clarify the roles that Richard (Nestor Carbonell) and Daniel (Jeremy Davies) play in the island's master plan, setting the stage for the prophecies of Daniel's mother, Eloise Hawking (Fionnula Flanagan), to play a bigger part in the sixth and final season. Dozens of other players flit in and out, some never to return. A few, such as Jin (Daniel Dae Kim), live again in the past. Lost could've wrapped things up in five years, as The Wire did, but the show continues to excite and surprise. As Lindelof and Cuse admit in the commentary, there's a "fine line between confusion and mystery," adding, "it makes more sense if you're drunk."

Lost Season Six
It’s taken a long time to get here, but finally, the last season of Lost arrives, with answers to at least some of the questions that fans of the show have been demanding for the past few years. In true Lost fashion, it doesn’t tie all its mysteries up with a bow, but it does at least answer some of the questions that have long being gestating. In the series opening, for instance, we finally learn the secret of the smoke monster, which is a sizeable step in the right direction. In terms of quality, the show has been on an upward curve since the end date of the programme was announced, and season six arguably finds Lost at its most confident to date. Never mind the fact that it's juggling lots of proverbial balls: there's a very clear end point here, and the show benefits enormously from it. Naturally, Lost naysayers will probably find themselves more alienated than ever here. But this season nonetheless marks the passing of a major television show, one that has cleverly managed to reinvent itself on more than one occasion, and keep audiences across the world gripped as a result. There's going to be nothing quite like it for a long time to come.