Grizz flop a shit ton, especially Marc Gasol. I'm surprised he didn't sprain his neck with all of those neck jerks. Z-Bo did a handful of times as well. Hell, I'd be willing to bet, if a fully impartial person, viewed the series, they'd say Memphis flopped just as much, if not more.
Ginobili and Parker make noticeable attempts to flop. You can actually tell they play the game straight up unless they don't get a couple calls, or their team starts to fall behind... then they miraculously lose their sense of balance and start falling all over the court.