For me, the ultimate action comedy would be set in Clearwater, Tampa, or Orlando (that General area) in Florida.
I'd select Ben Affleck as my director, and have a script that's in between Captain America: The Winter Soldier and American Hustle, in terms of tone.
Denzel Washington is my first pick to lead this cast, as a charismatic crime boss who is very well respected yet has a violent temper. He wishes to leave his life of crime and settle down but he just can't.
Matt Damon would play a rich patriarch who's trying to do as much for his family as he can, but in turn is a bit of an asshole.
Christian Bale plays a rich playboy type who doesn't realize some of the damage he causes.
Robert Downey Jr. is someone who works behind the scenes, and gives a lot of great advice and is a mentor and good friend.
Jennifer Lawrence plays a stereotypical beautiful girl, who uses her looks to overcompensate for everything else and shrugs off everyone 'below' her.
Scarlett Johansson would have a girl next door sort of role, someone that is the voice of reason and was there the whole time but you didn't quite 'notice it'.
Tom Hardy would be a cocky, brutal gangster who is sympathetic due to the fact that he needs the money for a dying relative.
Jeremy Renner is an intelligent, nice guy who always seems to get screwed over.
Set that up with a soundtrack from U2, OneRepublic, and Drake, with Hans Zimmer composing the background music and we are good to go.