Cleveland Cavaliers center
Twitter name: THE_REAL_SHAQ
Mostly motivational bons mot ("Be led by your dreams, not pushed away by your problems"); mama jokes ("ur moms so fat, when she goes swimming with whales, they sing 'We are family'"); and fan giveaways ("I'm at the fashion sq mall, any1 touches me gets 2 tickets.")
Twitter name: lancearmstrong
Not surprisingly, the "seven-time Tour de France winner, full-time cancer fighter" promotes his Livestrong campaign. He offered updates during his comeback tour last year ("On the plane to Limoges. It's about 120 degrees in here. Hotter than donut grease"). And even tweeted the birth of his baby ("Wassup, world? My name is Max Armstrong, and I just arrived. My Mommy is healthy, and so am I!").
Cincinnati Bengals receiver
Twitter name: OGOchoCinco
His brazen tweets are exactly why he's so fun to follow. When he's not posting twitpics of his workouts ("Triceps—I'm gonna be 220 when I'm done"), he's—what else?—tweetin' trash ("@ Shawne Merriman damit I didn't stutter, I never held my tongue before, you heard me loud and clear, and we can get in the boxing ring to.")