Lost is about the survivors of a plane crash who end up on an island where all sorts of strange things happen. As the series goes on, we discover more about the twisty past of the large cast of characters through flashbacks and also — in the present — about the nature of the island.
Without spoiling too much: a violent creature roams the woods, people who couldn't possibly be on the island walk around there regardless, and a shady corporation has been doing strange experiments there. More than one external force has it out for the survivors, and even the island itself seems to have a plan for them, one possibly connected to karma. Most of the drama plays out on a sunny beach or in a sumptuous tropical forest.
Lost is a series you get the most out of by starting from the very beginning, watching as pieces of a very elaborate puzzle start to interlock. The brains behind Lost — among them, creator J.J. Abrams of Alias and Cloverfield fame — are meticulous about drip feeding just enough new information in each episode to keep you guessing and hungry for more.
Considering they clearly scoff at linear storytelling, it is ironic that all the episodes need to be seen in order to not get, well, lost. Where for the first two seasons or so the stories jumped between the present on the island and the twisty past of the plentiful cast, by now there are also jumps into their future. It is to the writers' credit that you won't often get confused about where you are in the narrative. Because of a lot of casually referenced backstory, though, you might find yourself scratching your head regularly if you don't tune in every week.
The most regular complaint about Lost is a lack of forward momentum. Because of the trips into the past and several storylines running concurrently at most points, a cliff-hanger from one episode might stay unresolved until a couple of weeks later. Too many lingering reaction shots and a general unwillingness of everybody on the island to either ask an obvious, direct question or give a direct answer can also get on the nerves. Everybody is withholding information from everybody else for sometimes unbelievable reasons. It is an obvious way to extend some of the plotlines and to build tension.
I have to admit that I almost bailed on the series at the beginning of the third season when the first ten episodes or so stalled. The writers just seemed to be milking for time. Luckily, the series soon recovered with a clearer sense of purpose and I can't help but think the writers' strike actually helped the abbreviated fourth season, with just fourteen episodes. The creators claim to have the whole story mapped out until the end of the series, the next season supposedly wrapping it up. They were forced to speed up their storytelling to end the fourth season at the point they had originally planned, leading to some pleasantly compact episodes.