A tough but thought provoking question Darebear. It makes for a very good thread. :)
I love all my HK's - P30L, P2000 SK, USP 45C and HK 45C.
Each is special and has its own merits -- P30L & USP 45C are great for HD, P2000 SK & HK 45C carry very well.
I'd be hard pressed to choose just one...