In reply to phja:
They're both good and classics for a reason. I agree with Trangia that Tridentina is possibly a bit over hyped, but still very worth doing. It does get busy though so it's best done very early or better yet done after 12 (just make sure there are no thunderstorms forecast). The nice thing about Tridentina is the majority of it can be climbed on beautiful sculpted jugs the whole way up.
Personally my favourites are:
Delle Mèsules/Possnecker on the Sella
Tomaselli on Cima Fanes Sud
Punta Anna link up with Lamon/Formenton on Tofana di Mezzo
Degli Alleghesi on Civetta