Burn Notice is pretty good. It's about a spy whose identity has been erased by the Department of Homeland Security and all of his assets frozen, so he does freelance spy/detective work to make ends meet and find out who burned him. It's got Bruce Campbell in it, playing his friend in the FBI who's feeding the FBI bullshit so that he can clear his name and have his life back. Also, the mom from Queer As Folk is in it.

speaking of USA shows, try Psych. One of my favorite funny shows ever, about two friends who open a psychic detective agency, except neither of them is psychic--it's just that one of them is hyper-observant (think The Mentalist).

Also, Eureka is a good show and totally underrated/ignored. It's about a secret, government-run town full of geniuses. It's great.

Lie to me, with Tim Roth, is also pretty good.