Evans, Contador, Schleck(s), Cancellara, Cavendish, Horner, Voeckler, and Sanchez
I enjoy watching:
Evans - because of what he did in the rainbow jersey. Favorite Moment: Montalcino '10
Contador - because he has been a great champion, plain and simple. Favorite Moment: Giro '11 w/ Tiralongo
A. Schleck - because he's my favorite rider. Favorite Moment: actually challenging Contador in the TT last year in the Tour.
F. Schleck - because as someone said, they share the same brain. So to like one is to like the other. Favorite Moment: sacrificing himself on the cobbles, what a nice guy!
Cancellara - because he just wins and wins. Favorite Moment: 2007 TdF Stage 3, beats the sprinters in the last Km
Cavendish - see Cancellara. Favorite Moment: bunny hop in a Vuelta win
Farrar - because he's fun to watch. Favorite Moment: finishing 2nd on a TdF stage to Cav with a broken arm.
Horner - because he's finally getting to ride for himself. Favorite Moment: helping TVG in the Dauphine last year
Voeckler - because you just can't not like this guy. Favorite Moment: keeping the yellow jersey in 2004 up Plateau du Beille.
Sanchez - because The Hitch guilted me into it

. Favorite Moment: racing the Tourmalet with a broken something (arm?)
EDIT: Hesjedal too! Favorite Moment: His breakaway on the cobbled stage of the Tour.
So, a lot of big names, and an American and a Canadian.
Andy's my favorite though.
That said, I generally enjoy watching everyone, except Leipheimer. He's just dull.