A great premise to a series that very quickly fails to achieve it's potential. Season one is worth the watch but it quickly goes downhill. The writing is mediocre, the acting has it's flaws, Billy Burke (no matter how charismatic) is still Billy Burke, the pseudo-science and the apparent fact people don't know basic biology, situations that are unrealistic even for the subject matter ([spoiler] can you imagine all insects being against us? humanity would be done in a day, a gorilla that can't bash in a stupid elevator grate, etcetera [/spoiler]). I'm still gonna watch season 3 for completion's sake and I'm still entertained a bit but this could have been so much more.

Edit: Upon finishing Season 3 I must disagree with most/many people that it was the worst season. Besides a couple of annoying writing errors I enjoyed Season 3 way more than the second one. It got a bit annoying that a certain person kept surviving and that we, ofcourse, will never know what would have happened in Season 4.