What's this guy's deal?
1: When one does not quite understand a guy's deal

2: First used in Step Brothers by Derek's son while the family was eating dinner and Dale asked a question about Derek's story. Out of anger and confusion of Dale's stupid question the son muttered, "What's this guy's deal?", creating comedy legend.

3: Can be said in certain situations, such as: If a friend was doing something slightly vulgar and without purpose one might say, "What's this guy's deal?". Out of pure perplexion of that guy's deal. Commonly said to a group of people so perhaps one of them must understand.
Person 1: "Wow, Twilight was such a good movie. Full of inspiration of how the undead can still find love."

Person 2: "What's this guy's deal?"