In season one, in spite of the obvious threat of The Others and the fact that the characters had just survived a plane crash and were stranded on a mysterious island, "Lost" was a show where the characters could actually have fun, exchange some small talk, and have something to smile about. Gradually the show has gotten darker and more violent, and in many ways would become darker and more hopeless than ever in season 3 and 4. One of the few episodes in the latter two seasons (as of December 2008) which provided lots of light comedy and gave the cast (particularly Josh Holloway, Daniel Dae Kim, Dom Monaghan, and Jorge Garcia, who get the most screen time this episode) a chance to do something more presumably enjoyable recently, and a couple of those four have gone on record saying this was one of their best experiences on the show.
The episode itself is superb largely because while it has a life-affirming message of hope, it also thankfully acknowledges the point to which the show had come and the violent nature of many of the events on the island, in addition to how much the survivors had lost. It's a remarkably human script, one which portrays the characters without anything but their purest emotional traits. Hurley's determination to start the van is absolutely real, Sawyer's reaction to the beer is too, and their collective ecstasy when they get the van started is absolutely totally believable and human. Yet, there is a sad undercurrent to the whole affair, one which would not become entirely clear until later in the season.
The episode also benefits from particularly excellent direction courtesy of Eric Laneuville, truly one of the finest television directors working today. There is not a hint of amateurishness, not a hint of confusion about anything, and lots of neat, subtle little touches that stay on the right side of showboating. A really fun episode, but not a light one. The difference is huge, and "Tricia Tanaka is Dead" is most certainly a substantial episode, regardless of how many meteorites and jokes involving a Jesus statue and Hurley's mother's 'needs' it's got.