I listen to everything, specifically rock/80s/hip hop/dance&electronica when working out. I usually only listen to music when I'm lifting, though. When running, I like just hearing the sound of my breath and nature (I usually run trails) or watching TV if I'm on the treadmill.
Recently, and as ODD as it sounds, I've actually started listening to some reggae when lifting. It just puts me in such a happy place!!
Here are as many good workout songs as I can come up with off the top of my head:
Bone Thugs n Harmony - Notorious thugs (feat Biggie) -
I LOVE THIS SONG... it's a staple EVERY time I work out. 
Talib Kweli - Get by
Damian Marley - Welcome to Jamrock
The Roots - The Seed 2.0
Flo-Rida - Low
Timbaland/Keri Hilson - The way I are
Earshot - Wait
Xzibit - Get your walk on
Queens of the Stone Age - 3's and 7's
Common - This is music
Outkast - Jazzy Belle
Outkast - Atliens
Crossfade - Cold
Damian Marley - Catch a Fire
Scorpions - Rock you like a hurricane
Scorpions - No one like you
Closer - Lacuna Coil
Slipknot - Before I forget
Tribe called quest - Can I kick it?
Foghat - Slow ride
Kanye - Jesus walks
Papa Roach - Forever
Ratatat - Get 'em high
Type O Negative - Christian Woman
Zion I - Trippin'
Li'l Wayne - Lollipop
Bob Marley - One Love
Black Sabbath - Paranoid
Killswitch Engage - pretty much anything by them is fine
Stereo MCs - Connected
ACDC - Hell's Belles
Axwell - Watch the sunrise
Sponge - Plowed
Bob Marley - Stir it up
Cascada - Every time we touch
Eric Clapton - Layla
Beats International - Dub be good to me
Justin Timberlake - Chop me up (feat Timbaland and Three Six Mafia)
Bon Jovi - Run away
Mute Math - Chaos
Dragonforce - Through the fire and flames
Lupe Fiasco - Superstar
Okay, that's it for now.

Sorry for the long list!