Pretty much any '80s hair-metal works. Notable examples include:
Bon Jovi, "Dead or Alive" (if you can sing, deliver a good, strong, impassioned version of this at any karaoke bar on Earth and you won't go home alone)
Great White, "Once Bitten Twice Shy" (just don't listen in an enclosed space.... ;-))
Guns 'n' Roses, "Welcome to the Jungle"
Warrant, "Cherry Pie"
Whitesnake, "Here I Go Again"
Motorhead, "Born to Raise Hell"
Absolutely ANY AC/DC... "Rocker," "Back in Black," "Big Balls," "Meltdown" and "Stiff Upper Lip" get points as DJ songs, and "Ride On" is one of the all-time great songs for getting over a girl. Actually, it's one of the all-time great songs, PERIOD.
Non-hair great DJ songs include:
Kid Rock, "****y," "American Bad@ss," "Prodigal Son," "Cowboy," "Where U At Rock," "Early Mornin' Stoned Pimp," actually, fvck it, pretty much any Kid Rock. I would be remiss, though, if I didn't bring to your attention his duet with Snoop Dogg, "World Class Sex Rhymes," which is possibly the greatest DJ song EVER.
Archie Eversole, "We Ready"
Jimi Hendrix, "Easy Rider," "Crosstown Traffic," "Red House"
Eminem, "Till I Collapse," "Lose Yourself," "Superman"
Snoop Dogg, well, pretty much anything, but I'll go with the classic, "Gin and Juice," or the newbie, "From da Chuuuch To tha Palace."
Ice Cube, "Down for Whatever"
Nas, "Made U Look"
Rob Zombie, "Never Gonna Stop" (the version mentioned at the top of this post is the Black Cat Crossing mix, which is the entry music for the WWE's Edge. Look for it on the WWE Forceable Entry CD, or just download it with the file-sharing engine of your choice.)
Blues Traveler, "Carolina Blues," "Hook"
P.O.D., "Boom"
And my personal favorite, the key to the whole CD, without which it will simply not be complete:
Dropkick Murphys, "The Spicy McHaggis Jig."