Stuff I've seen/shot/owned/drooled-over:
Glock 36 - Single stack .45acp, 6+1 capacity. Grip is very narrow and recoil is sharp into the palm as a result. Like all glocks I have shot, the trigger well is at a bad angle and my finger (the way my hands are built) rubs against the bottom of the well. G21 is simply too big to conceal... I own one and have several friends who also own one. G30 is pretty good, but the doublestack well still prints quite a bit without being inventive.
Various 1911's - Heavy in the government models, but the most concealable full sized pistol on the market, IMO. Were I to carry any 1911 made, I'd choose either the Kimber Ten II for its polymer frame (to lighten weight) or a Colt Commander with aluminum frame.
Smith & Wesson 25 and 625 - I'd carry one of these 45acp moonclipped wheelguns in a heartbeat.