I really liked "Acts of Vengeance"...it had a very interesting and unique story-arc, I thought.
If you could re-imagine AOV, who would you pit hero against villain that they haven't faced ever? Here are just a few of my dream bouts (and I'm pretending "Civil War," "House of M," and other recent major events didn't happen)
Thor vs. Carnage
Spider-Man vs. Crossbones
Nightwatch vs. Magneto