Can't go wrong with a Glock 19. Look at the list of guns that were just used in the IDPA championship. Lots of various 1911s but the most popular type by far is the Glock.
That being said - I also shoot a 1911 for fun. One good point about the 1911 platform is that it lets you practice malfunction drills more than the Glock.
Ducking for cover.
At the last match, I shot - that certainly was the case for quite a few and mine has seized up in two matches!
I'll shoot my 26 or a revolver once in awhile to get trigger time.