Ughh, the helicopter episode was terrible! I really didn't like Romano, but poor guy. I think that episode was a bit tasteless, how he died. First he gets his arm cut off and then an helicopter falls on him!
I like Elizabeth too. I think she will leave the hospital and go back to England, or something like that, but I don't think they'll kill her off. (At least I hope they won't!)
The character I like the least right now is Sam. She's a bit annoying and doesn't treat Luka right.
I agree with LordAndry, Abby is a good character. I liked it when in the season finale, she told that pacient who was a Math teacher that he should ask for
Dr. Abby Lockhart
Anyway, I got carried away, hehe

I'll stop now.