If the Heavy loses a big pot with a good hand, sometimes he will scream, overturn the table and unleash Sasha. Then he'll glower at the rest of the table as it turns out to be all in his head.
The Player throwing down that first ten grand. Clearly, you are a Badass.
Any time three or more people (yourself included) go All In.
Even better, if you win the hand and bust out two or even three players at once, especially if they're the last ones left, since nearly all games end with either you busting out or you busting out the last one player. You better be grateful it happened, because it's only once in a blue moon.
If Tycho is the first one eliminated, he'll reach into his pocket, only to jump when he hears the others cock their weapons in defense. A distinct whirring sound starts up and his eyes widen—the Heavy is spinning Sasha at him. Not only that, but Max has his Luger pointed at him and Strong Bad brings out the nunchuck gun.
The Heavy, Max, or Tycho praising your winning the tournament. Definitely a worthy achievement.
Winning their items. You feel like a champion afterwards.
The fact that someone at the table beat Pom Pom, who's good at nearly everything.