vince is right about season two, though - it throws you in at the deep end character-wise even more than season one did. but bear with it for a few episodes and you'll start getting rewarded.
definitely the season that benefits most from a re-watch.
edit: whoa, vince's ranking is basically spot on (i'd go 5>1 but there's not much between them). which amazes me cos i've never seen anyone fully agree with my ranking before!
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And if you don't know, now you know.