According to GAMA sales numbers, the Cirrus SR22 outsold every other piston single in 2013, including the entry-level SR20.
Whats interesting is that the SR20 arguably has a broader mission profile than the SR22. Cirrus even markets the SR20 as a dual-role aircraft that can function as a trainer and distance traveler. Perhaps that is why SR20s are more likely to end up on flight school ramps than in personal hangars.