S&W 625s are great. Mine is a gem. The Ruger P-90 and P-97 are good, too (I prefer the P-90 of the two). I'd really like to try a steel framed Witness in .45 ACP, but that's way down the list. The Ruger convertible Blackawks in .45LC/.45ACP are good, too, IMHO.
Never shot a Sig .45 Auto, but if they made a Sig Pro in .45 ACP, I'd be all over that.