+1 on the two previous recommendations for the Smith & Wesson 5906.
I found this one, as a police trade-in for a good bit less than $300. It was pretty rough on the outside and dirty, but perfect mechanically. If you're willing to break one down all the way, clean it thoroughly, and bead blast it, you can get it back to, pretty much, brand new condition:
, on Flickr
Maybe a new set of grips for ~ $16.00 as well. MecGar makes 17 round mags for it also.
Oh, and if it ever quits shooting, it would make a terrific instrument for 'blunt force trauma'