I wasn't on any of those three, but I was on Slime Time LIVE back in it's prime.
My family was at Universal for the day, and my youngest brother wanted to be either on the show, or in the "live studio audience". So him and my mom waited in line from the time the park opened until around noon. Meanwhile my Dad, sister, and I enjoyed ourselves at Universal.
Around noon we went back to the studio, because if your family got picked you went in the audience. Turns out my brother was a year below the age requirement, so my sister and I who hadn't been in line for four hours got to audition.
They lined up about thirty of us twelve year-olds and told us to act crazy, and the craaaaaaziest kids got to be on Slime Time LIVE. Not being very creative or crazy, I spun in circles. While spinning i fell over into a shelf or some boxes (I can't really remember). I guess they felt bad for me and let me on the show!
That little bump on the head was 100% worth it. In my little twelve year-old mind I probably would've cut off one of my feet Saw style to be on the show, so the head bump was a small price to pay.
Me and my sister were given totally new outfits to put on (I remember the shoes were three sizes too small, but that was another sacrifice I was willing to make). We got to meet Dave, Jonah, and Jessica, so it was pretty much the greatest day of my life up until that point.
The show we we're on was Clockstoppers themed, so we went "bobbing for clocks". My sister beat me on live TV in front of the entire country, I still haven't forgiven her.
Anyway, she lost in the next round, and we got some free T-shirts and were sent on our way. Pretty awesome day overall.