Not one or two great battles. I mean, total number throughout their career where they've both dished out and received a lot of punishment, resulting in great fights.
Shogun and/or Big Nog come to mind for me.
Diego Sanchez comes to mind
/\/\/\ Oh yeah, that's a great one, Rick.
Scott Smith comes to mind for the amount of "HOLY SHIT!" moments in his career
Struve, Lawlor, JDS
Hendo
Matt Brown will be in that discussion some day. Already on his way.
Hendo entered my mind too, Striking.
Penn, Diaz, Condit, Faber, Rory, Mir, Chuck, Edgar
Robbie. Everytime I've ever watched that dude fight im expecting someone to be unconscious at any moment.