This second series of Roswell is the best by far. The characters are more familiar, and the storyline (though at times seeming a little far fetched) develops nicely, tugging at the heartstrings on many occassions. Some of the episodes have evoked tears - I think the high point of the series was when my brother made me rewind the tape in "The End Of The World" just so he could watch one particular scene over and over again. There seems to be more of a general storyline in this series, though there are still many smaller subliners. The end episode ("Departure") is one of my favourites - along with "The End Of The World" and "Cry Your Name", and I think that all three deserve praise for their sensitivity towards the storylines and just for the great standard of acting not seen so much in the previous series.
If you like to watch something which makes you laugh (this certianly does...Kyle's character is explored much more widely, to provide us with some excellent one-liners) and cry, and just want to watch over and over - then you should buy this series. It truely hasn't gained the recognition it deserves.