More than I can count/remember, but here's some:
Stealth - code bronze (failed launch), evac'd in the station
Colossus - chain dog misalignment error, evac'd on lift hill
Nemesis Inferior - more than once due to errors, never evac'd except during a training exercise on the lift hill
Swarm - stopped in the break run for about 5 mins, returned to station as per normal.
Slammer - ride not lowering, stuck for about 10 mins
Oblivion - the usual lift hill stoppages so someone can have their camera/mobile removed
Skyride - stops all the time obviously to allow disabled passengers on and off, however, there was one time we were stuck for about 5 mins
Monorail - technically not, but we happened to be on a train that stopped on the middle of the circuit, to allow an evac training to take place on another train.
Duel - power outage during the blizzard in april
Air - stuck in brake run for 5 mins
Nemesis - stopped on lift for 2-3 mins, restarted
I'm pretty sure there have been others, but I can't remember them, and that's not including the ones I've attended as an operator