"Glorious" by Andreas Johnson (I think). It always reminds me of when I was doing my GCSEs, because there were builders at my school at the time doing extensions on the building, and they were working in the corridor outside my classroom where we were having a revision lesson, and they kept playing that song.
Dido - "Here With Me". That one has bad memories relating to my ex so I don't like to hear it any more (although I've got Dido's album that it's on).
"Simply the Best" by Tina Turner always brings back memories of the gymnastics displays we did in school, because that was the song used every year for the vaulting display of the top year.

I didn't do the vaulting at school (just did the floor routines), but we got to watch it.
"Under the Bridge" by All Saints - because me & some of my friends were due to sing it in the school Talent Show one year, although we didn't end up doing it in the end.
"Hot Stuff" by Donna Summer. I was at school when the film The Full Monty came out, and me & my friends loved it. I remember once we were in a silly mood in the queue for dinner, and we were singing it, and all started doing the dance that the characters in the film do in the dole queue... :lol:
They're the ones I can think of off the top of my head.
Edited for a few names I forgot.