So far I think season 3's got the tightest season, however season 4's giving it a run for it's money in terms of amount of great episodes. And season 1 and 2 just don't compare. They're really good but seasons 3 and 4 blow them out of the water.
Agree to disagree. Personally, I think season 1 is the easiest season to watch - perhaps because it was so fresh. I mean, POI's pilot is my all time favourite pilot - I could watch it again and again. The same is true for all the episodes. I'll admit that season 3 has more complex and layered stories and scripts, but season 1 is pure fun - simple stories, told well
Season 2 was probably strongest around Reese's imprisonment and the resolution of the Kara Stanton/Mark Snow issue, the introduction of Shaw and Leon Tau being 2 real highlights. So overall, I'd put it on a par with season 4.
Season 3 takes it to another level in terms of storylines that develop slowly and build to a major climax -with only a couple of filler episodes, and of course the 2 major storylines (Carter's personal war with HR and its aftermath) and Vigilance/the birth of Samaritan.
To be honest, I still feel that while season 4 has had some standout episodes the overall storylines aren't as tight ( Season 3 would be the tightest season of all ) . The season 4 episodes seem to have a mishmash of different plots and storylines. True, it has had several (like 5 or 6) real stand-out episodes, but I still feel like the shape of the series has been pretty hard to gauge (the Stock Market crash stuff was pretty strong, as was Greer's origin episode, and Pretenders).
Also, season 4 has had some great gunfights (mostly between Root/Shaw and Martine) but no fistfights to approach Reese's prodigious ass-kicking from season 1 and 2 ( I mean in the show's first 5 minutes he kicks the crap out of a bunch of punks, and Reese vs Hersh was epic - although in season 3's 4C Reese beats up half the people on the plane).
The closest thing was Katherine Winnick's guest role, but even that didn't have Reese's usual flair ( I've noticed that Jim Caviezel seems to be doing less stunt-fighting, has he developed some injuries we don't know about ?)
In season 4 it almost seems like they are shopping around for a Shaw replacement, with Harper Rose and Det. Silva, but can't pick one.
If Nolan has taken a step back, this would certainly explain some of the difference in the overall feel of season 4, but hey if people like that fair enough, this is just my opinion.