USP 40
I have a USP in 9, 40 & 45, they're awesome guns, durable, accurate, incredibly reliable. The only detraction is if you have small hands, then I would consider a grip reduction like many are doing to Glocks.
I agree with SWChad, there are plenty of mint used USP's for sale on various boards for 1/3 to 1/2 of MSRP. I picked up a like new USP 40 V1 with 10 mags and a case for $500 and after 5k rounds, it has never failed. You'll never regret buying it.