This is really a tough question because it depends on your mood as much as anything. I can't say which round I like to shoot most. I have shot guns I hated but it had nothing to do with the caliber. I guess if you pin me down it would be my M&P 9mm.
A full size 1911 Government model is in a different league than any other handgun. A good 1911 is about as close to shooting Nirvana as you are likely to find.
+1 for compact. I feel like they point more naturally in my hands. I tend to be more accurate with full-sized weapons, but I enjoy shooting those compacts at around 4" barrels.
~LT
My Full size S&W 1911 Performance Center. It is made so precise its ridiculous. Its a phenomenal gun to shoot. That said, its been in the safe a little too long. Likely only shot it once this year.