Here are some that are on my MP3 Player that I take to the gym...I like some of them because of fighter highlights, ring entrances, etc.
Assassin - Don't Like You
A Perfect Circle - Magdalena
A Perfect Circle - Counting Bodies Like Sheep
A Perfect Circle - Blue
Alkaline Trio - Stupid Kid
Antiflag - Sold As Freedom
Breaking Benjamin - Blow Me Away
Boot Camp Click - Operation Lockdown
Bun B - Late Night Creepin
Cream - Badge
Damageplan - Pride
Damien Marley - Welcome to Jamrock
Dark New Day - Brother
David Banner feat. Static - Crank it up
Days of the New - Die Born
Deftones - Teething
Delinquent Habits - Return of the Tres
DMX - Ain't No Sunshine
Dope - Always
Dropkick Murphys - Pipebomb on Landsdowne
Drowning Pool - Love and War
Edgewater - Eyes Wired Shut
Edgewater - I Won't Back Down
Edgewater - Submerged
Endo - Leave Us Alone
Faith No More - Falling To Pieces
Fugazi - Waiting Room
Geto Boys - G Code
GWAR - Black and Huge
GWAR - Love Surgery
GWAR - Maggots
GWAR - Years Without Light
Gypsy Kings - Djobi Djoba
Hole - Gold Dust Woman
In Flames - Cloud Connected
Iron Maiden - 666 Number of the Beast
Jimi Hendrix - All Along the Watchtower
Joe Walsh - Turn to Stone
Kardinal Offishall - Kill Bloodclott Bill
Kasabian - Empire
Kenji Kawai - Voyage to Avalon
Santa Esmerelda - Please Don't Let me Be Misunderstood
Killing Joke - The Wait
Kreator - Grinder
Less Than Jake - Surrender
Long Beach Dub All Stars - Trailer Ras
Lo Pro - Sunday
Mighty Mighty Bosstones - Where Did You Go?
Misfits - Dig Up Her Bones
Misfits - This Island Earth
Misfits - Pumpkin Head
Mobb Deep - Shook Ones
Morningwood - Easy
Muay Thai - Ram Muay
DJ Spooky - B-Side Wins Again Remix
NOFX - Drugs Are Good
Osaka Popstar - Wicked World
Osaka Popstar - Man of Constant Sorrow
Pennywise - The World
P.O.D. - Southtown
P.O.D. - BOOM
Pressure 4-5 - Beat The World
Red Hot Chili Peppers - Higher Ground
Rocky Soundtrack - Training Montage
Rocky Sountrack - Going the Distance
Rolling Stones - She's So Cold
Sevendust - Face to Face
System of a Down - The Metro
Tantric - Astounded
Ted Nugent - Stranglehold
The Beatsteaks - God Knows
The Misfits - Bullet
The Misfits - Dust to Dust
The Misfits - She
The Pharcyde - Runnin
The Ramones - Beat on the Brat
Freya - The Sword
Time Zone - World Destruction
Too Short - Blow the Whistle
Tool - Lateralus
Tool - Parabola
Turbonegro - All My Friends Are Dead
TV on the Radio - Wolf Like Me
Wu Tang Clan - I Can't Go To Sleep
Smashing Pumpkins - That's The Way (My Love Is)
Misfits - She
Born is the Enemy - Daysend
Adema - Cold and Jaded
Misfits - Skulls
Red Hot Chili Peppers - Tell Me Baby
The Ramones - Glad to See You Go
Misfits - 20 Eyes
Hard Fi - Suburban Knights
Evolocity - 4th Wise Man
Erase the Grey - Rain
Erase the Grey - Pariah
Molly Hatchett - Flirting With Disaster
Warrant (shut up) - Uncle Tom's Cabin
Dead Prez - Hip Hop
Collie Buddz - Come Around
BIG & Puff Daddy - VICTORY
This list is from a few months ago, so I have a much different playlist now...but hopefully this gives you one or two that you might like.