I'm sure lots won't agree but hate the Cherokee six, bad for loading and just a horrible bit of junk IMHO
Didn't mind the cherokee six really, was just a bit of a pain when it had a bit of weight in the back combined with that long nose... almost like taxiing a tail-dragger.
Someone else has already said it, but I'll say it again the PA32-RT (turbo lance) was a horrible aircraft IMO. Performance was a real disappointment and could potentially bite you on the arse if not flown properly.
A lot of people here don't seem to like them but I have a soft spot for the c172, especially the later SP models with the 180HP Lycoming. Have also flown the XP model and that was better once again. Much prefer a 172 over a warrior (got lots of time in both).
Loved the A36 Bonanza though, an absolute delight to fly.
Probably had the most fun flying an RV7A, but the RV10 was also very impressive (and comfy too Jaba!)
Coolest thing I ever flew... Gyroflug SC-01 Speed Canard (bit like a long-ez but roomier and factory built)