I think that, for a 30's-40's style team, characters like Indiana Jones, the Shadow, the Phantom, the Rocketeer, & others would work well for a team in that era.
However, for a more "modern" team, perhaps these characters are all potential candidates:
* John McClane/Jack Burton (obvious reasons stated before)
* MacGyver
* Lara Croft (for a more "modern" equivalent of Indiana Jones--not sure how this'll work)
* James Bond (the character has sort of been made "timeless" due to the movies), or Jack Ryan
* LeStat (a famous "modern" vampire)
* Magnum, P.I.
* One of Jackie Chan's reluctant heroes (usually named Jackie).
Then again, some sci-fi/mystical elements wouldn't be totally uncalled for, so perhaps Arnold Schwartzenegger's character from "Predator" (or even a Predator itself) could be viable.
As for villains, there's always a fair share of foes from film. Whether it's a Predator on the loose, a evil plot from the forces of S.P.E.C.T.R.E., members of organized crime or a drug cartel, neo-Nazis, terrorists, or even something like the beast from "Jeepers Creepers," Hannibal Lector on the loose, an outbreak of Aliens (thus the presence of a Predator), or even a run-in with the current generation of Sawyers/Hewitts (ala the Texas Chainsaw Massacre) may be viable.
