Chris, everyone loves Tyrion! He's so wonderful and Dinklage really brings him to life perfectly.
I also like, bearing in mind that I haven't seen series 2 yet, Daenerys Targaryen, Jorah Mormont, Arya Stark and Robb Stark. I have always liked Sean Bean (especially as he played Richard Sharpe in the Bernard Cornwell books I have mentioned in other posts) and so I guess Eddard Stark is going to be included in my list of characters I like from series 1. How this will change for the second series I don't know. I think Arya is going to be a really interesting character but I guess I will have to wait and see.