If you want instrumental then try something by Two Steps From Hell, Epic Score, or E.S. Posthumus. There is also a cool song called Clubbed to Death which is also instrumental. Some songs with lyrics could include Won't Back Down by Eminem, 24 by Jem, and The End Is the Beginning Is the End by Smashing Pumpkins.

I just happen to be making a playlist for the boxing gym right now

"Bullet With A Name" - Nonpoint
"District Of Misery" -Oceano (this would need a really brutal fight scene)
"Ante Up" -M.O.P. (a song about robbin' *BLEEP*s! lol)
"We Will Rock You" -Queen (doooiiittt!)
"Kern Craft 400" -Zombie Nation (I have no idea why, but that'd be awesome)
"Ebolarama" -Every Time I Die
"Like A Virgin" -Madonna (bahahahaha! seriously, who wouldn't remember that fight scene!?)
"Stuck Pig" -Glassjaw
"Talk Is Cheap" -Comeback Kid
"Put Yo Hood Up" -Lil' John (if you're filming a superficial "Fast and Furious" type movie lol)
"What's My Name" -DMX (If DMX is in the film lol)
"Black Math" -White Stripes