I've got three that are especially accurate:
S&W Model 46: This is the plain finish version of a Model 41, the "Highway Patrolman" of target 22s. The matte finish doesn't inhibit the accuracy.
S&W Model 14: This gun is amazingly accurate with 38 SPL wadcutters.
Colt 1911 Series 80: A trip to Wilson Combat turned this into a real target pistol. If anyone ever tells you that a Series 80 can't have a good trigger pull, don't believe it.