Dog with a Blog to Out of the Blue

At the end of the episode "Guess Who's a Cheater", Stan says "Good Luck, Charlie", just as Teddy Duncan does on that show

Good Luck Charlie crossed over with Austin & Ally

Austin and Ally appear on an episode of Girl Meets World. Bringing the Disney Channel Live Action Universe into the Westphall Universe

Continuation of Boy Meets Wolrd

Boy Meets World and Step by Step both had episodes at Disney World and whiel in Disney World Eric from Boy Meets World met Dana from Step by Step.

The family from Step by Step was in the middle of a barbeque outside when Urkel from Family Matters came (literally) crashing in on the jetpack he had built on the last episode of Family Matters.

Family Matters was a spin-off of the character of Hariette and Carl Winslow from Perfect Strangers

Perfect Strangers' featured a game show segment in which the toilet was provided courtesy of Cunningham Hardware in Milwalkee, WI, owned by Howard Cunningham of Happy Days.

Out of the Blue was a spin-off of Happy Days