I'd argue Champions League for a few reasons:
- We've never won it: Would be special for Aguero, Silva, Kompany etc to tick it off their list.
- Gains us access to the Super Cup and the club World Cup (so a potential to win 2 more trophies. We haven't won either previously).
Also, it would be quite funny seeing Liverpool fans faces after we over-shadow their greatest ever season.
Personally, I'm confident we will win atleast 2 more trophies this season. Both League and FA cup are there for the taking. What a great position we'd be in knowing we had The league wrapped up and two finals to look forward too!