What songs sound the same to you...or similar. Maybe the introduction reminds you of something else...or the melody...or there's a guitar riff that sounds more like a guitar rip-off.
Here's a few to get things started.
An obvious one is the introduction to Kenny Loggins Footloose and John Cougar's The Authority Song.
Flaming Lips Fight Test sounds just like Cat Steven's Father and Son to me. I can sing Father and Son almost word for word to Fight Test's music.
There's a song by Blue Rodeo called Know Where You Go. The intro to this song always reminds me of Pink Floyd's A Pillow Of Winds.
Wanna play? Name some other similar duos. Direct rip-offs and remixes like the rappers use don't count.