What's Happening!! and What's Happening Now!!

Will: I even found my What's Happening!! home game!
Carlton: What's Happening!! or What's Happening Now!!?
Will: What's Happening!!
Carlton: Nitto, I get to be "Rerun."

What's Happening!! was an American sitcom that ran on ABC from 1976 to 1979. It dealt with the antics of Roger Thomas, Dwayne Nelson and Freddie "Rerun" Stubbs living in Watts. After the show's success, a revival was produced entitled What's Happening Now!! that ran from 1985 to 1988 in first-run syndication.

Rocky

The sequence where Will trains to get ready to fight Omar is a parody of the same scene from Rocky, a 1976 film starring Sylvester Stallone as Rocky Balboa. Rocky tells is about a washed-up boxer from Philadelphia who gets a shot at the world heavyweight title. Stallone also wrote the argument and was nominated for an Academy Award for best actor and the film won for best picture. Its music theme, also heard in this scene, became a classic which often played at various sporting contests.

The Fresh Prince of Philadelphia?

The title screen near the end of the episode is a spoof of the shows actual title. It's in reference to Will wanting to stay in Philadelphia.