Axel F (aka The Beverly Hills Cop Theme) by Harold Faltermeyer
Season 5 Episode 18: Meet the Quagmires
It's the first episode of the Cleveland Show.
Technically, Cleveland leaves Quahog in episode one of The Cleveland Show, but the last main appearance of Cleveland in Family Guy was in Road to the Multiverse where he is a Disney-style skunk in the Disney universe. He is mentioned in the next episode, Family Goy, as having left.
The episode is "I Love L. Gay" which is Episode 14 Season 8.
Harder, Better, Faster, Browner
Meet the Quagmires is episode 18 of season 5 of Family Guy.
Meet the Quagmires
Season 8|Episode 18
Season 5 Episode 18: Meet the Quagmires
There isn't an episode that features Peter and Glen in school together but you may be thinking about Season Five|Episode Eighteen Meet the Quagmires
You Can Hear It In The Family Guy Episode Entitled Meet The Quagmires.
The only episode that I remember them dancing in was the episode that was titled "The Ghost at Maiden's Peak" but pretty much everyone was dancing in that episode.
seson 1 episode 18
Episode 4.04 - "The One With The Ballroom Dancing".
You can find it in the Season One DVD release. It's Episode Twenty "Cleveland's Angels"
I don't recall any episode in which Gaara is dancing.
the episode was called "the fire bending masters"