Well... I haven't been actually "stuck" on a ride, but i've been on them when they messed up.
When i was about 6-7 years old i was on one of those bumble-bee rides, everything was going great, then oil just started spraying all over people.
The excact same thing happened on the Baloon ride at carowinds in 1996 -1998 (can't remember which year), but lucky for me i was jsut standing in line.
Another time i was on this ride called "Hurricane" (I don't know the ride type)and the ride started moving,then my lap bar unlocked and went all the way up, even though it's litteraly impossible to fall out of one of those rides unless your standing up, I was still scared as hell(i think i was about 8 or 9 when that happened.
And i was also on an octopus ride about a year or two ago and it messed up and all the ride-op was doing was making the cars go down, then back up, then nothign woudl happen, and it would keep repeating like that.
Other than those I've only been in-line when a ride got stuck/ broke down.