Up until a couple months ago I would have said My Ruger Hawkeye Alaskan in 375 Ruger. Now I think I've moved over to a Savage with a 19" McGowen 358 Winchester barrel. It will put 3, 200gr TTSX bullets into right around .5" (assuming I don't blow it). The 375 hits harder and still shoots under 1", but it weighs 1.5# more than the 358.
For a handgun it would have to be the 6.5" S&W model 610. That's about the only handgun I carry in the field any more.
Andrew