I'm biased, but my favorite was when he was pumping up Willie before the 2008 Illinois game:
"Big man's game, go dominate this thing."
Honorable mentions:
"If you wanna get some you better bring some right? If you wanna get some you better bring some."
"Get your dad gum chili hot right boys? Get that chili hot."
"No excuses, no explanations, do what we do - let's ride."