Vergil: ...and I got a bigger d!ck.
Nuff said. :troll:
Seriously, I personally loved Mission 3, aesthetically speaking... I simply, uhm, loved the colours. It's stupid, I know.... >_<
And I really liked the interactions between Dante and Vergil in the beginning, when they are still collaborating.
Another thing, the custscene for Mission 20. It raises so many philosophical/political problems in just a few lines, that I simply can't stop theorizing about it.
Finally, the cutscenes in Vergil's Downfall when Vergil confronts Kat and Dante... Even if I thoroughly hate the comic-like style, the dialogue I really loved. It depicts a man falling to pieces before his insecurities, and I can relate a lot to him, it struck a chord inside me. So yeah, those are my favourite.