"Y'all gotta wanna have it!"
"Y'all, hard work beats talent when talent refuses to work hard!"
One of my favorites or least favorites depending on my matchup:
"All right y'all, time for some bull in the ring!"
My definitive favorite, however:
"Y'all, get a quick water break before we wrap the day up with some good ol' Oklahoma and sprints!"
Well, the last two parts are kinda crappy sometimes, but water breaks rule when it's 105 outside.