45 acp has been my main carry since I started carrying, and will continue to be. Currently in my springfield 1911 mil spec, soon in my V12. Although I do want to get a small 9mm as a bug. Prob a keltec pf9 or something similar.
oh yeah, as for the ammo I carry. Currently my most carried load is the federal 230 gr HST, but I do normally keep a couple mags worth of the 185 gr +p hst loads on hand, and my 2 10 rd mags are currently loaded with 230 gr gold dots.