I'll begin with my Super Hero team, I felt that certain actors that played in the X-Men were too old to play certain roles or... some were just too young to be in the same era as others, while a couple of them were just wrong. This is the cast that i would have chosen for the X-Men. Some I kept, others I added, while a coule I changed.
The Atom:John C McGinley
Superman:Tom Welling
Batman:Christian Bale
Wonder Woman: Jessica Biel or kate Beckinsale
The Flash(Walley):Ryan Reynolds or Neil Patrick Harris
Green Lantern(Hal ) David Boreanaz
Green Arrow: Joaquin Phoenix or Keifer Sutherland or justin Hartley or jason Mewes
Martian Manhunter:Phil Morris
Black Canary:Alain Hoffman or ellen page
My Cast List for an Alpha Flight movie -- going with the original volume 1, issue 1 lineup here (no links cause I'm lazy). The challenge here was to keep the casting limited to Canada, but I just couldn't do it:
Guardian -- George Clooney (after his bad turn as Batman I am willing to give him a second shot at comic movie success)
Shaman -- Adam Beach
Langowski/Sasquatch -- Brendan Fraser
Snowbird -- Charlize Theron
Aurora -- Marion Cotillard
Northstar -- Johnny Depp (yeah, he's neither French-Canadian nor French, but he could pull it off)
Marrina -- would probably cast an unknown for this one...the makeup would be intensive anyway...
Puck -- Peter Dinklage (and yes, he is a real little person -- his agility feats could always be done by CGI if it's a problem)
Heather Hudson -- Alicia Witt
It's not perfect, but there you have it...
Edit: Nathan Filion could also make an excellent Guardian, but is a bit young for the role IMHO...