The first season was great. Scott - the show's much more than that, the island itself is like a character. I loved all the mystical elements at the beginning, and how it was handled, but after the first season it just wasn't the same. Recently I found out JJ Abrams was only writing on the show for the first few episodes, and he had a lot to do with the fantasy aspect. Maybe that has something to do with it.
season 1: amazing
season 2: shitty at times but has an amazing last few episodes
season 3: all shitty with one good episode