When Our Favorite Fictional Worlds Collide, We Get Great Episodes of TV

What happens when one of your favorite television shows visits another one of your favorite television shows? Magic, that's what! There's a certain feeling you get from finding out your favorite characters exist in the same fantasy world as another one of your favorite characters, like you've been let in on some very special little secret (never mind that everyone else watching is in on that secret, too).

While some shows have recurring crossover characters — like the wonderful sharing of Ursula Buffay (Lisa Kudrow) on Friends and Mad About You — others are just a one-off, like the appearance of the cast of St. Elsewhere on the classic sitcom, Cheers. More recently, Parenthood jumped over to About A Boy and The Simpsons and Family Guy met in an epic battle (although that's not our favorite Simpsons cross over — you'll see). All this, plus the time Ray Romano met Fran Drescher or when Urkel paid a visit to the Tanner household qualify as the best crossover episodes in TV history.

Parenthood and About A Boy (2014)

[caption id="attachment_440869" align="aligncenter" width="495"] [Photo: NBC][/caption]In Season 1 of About A Boy (Episode 7, "About A Poker Night"), Will hosts a poker night (did you see that coming from the title?) and who should walk in the door as a guest but Crosby Braverman (Dax Shepard), with his baby daughter Aida in tow. With both being set in the Bay Area, it makes sense that the two worlds exist in tandem. The best part though is former bad boy Crosby changing Aida's diaper on the poker table — gold stars for character consistency. Now we'd love to see About A Boy actors return the favor on Parenthood. A chance meeting between Max Braverman and Marcus, perhaps?

Mad About You on Friends (1995)

This is one of our favorite ongoing TV crossovers ever. With Lisa Kudrow already playing Ursula on Mad About You before she started playing Phoebe on Friends, the latter decided to give Phoebe a twin — the Mad About You waitress Ursula being the natural choice. Ursula appeared on Friends many times, but the best crossover episode was "The One With Two Parts: Part 1" (Season 1, Episode 16) when Mad About You's Helen Hunt wound up in the Village, mistaking Phoebe for Ursula at Central Perk.

Family Matters on Full House (1991)

Annoying neighbor Steve Urkel (Family Matters) appears in San Francisco when he's visiting his cousin who happens to be BFF with D.J. Tanner in "Stephanie Gets Framed"(Season 4, Episode 16). He helps Stephanie out with her new glasses and obviously drops the line "Did I do that?" John Stamos later made an appearance as himself (and references his role on Full House) on Step by Step — another TGIF show Urkel appeared on — thus throwing the whole universe on its head.

Buffy the Vampire Slayer on Angel (1999)

When Angel left Buffy he got his own spin-off that picked up right after his exit. So with the two already deeply rooted in the same world, it made sense for them to crossover. A lot. Cordelia Chase, Wesley, and Spike all became Angel regulars, and Angel himself made a few visits to Sunnydale. The best crossover of the two, however, was "I Will Remember You" (Season 1 Episode 8), where Buffy follows Angel to L.A. There, his curse is lifted, they fall in love all over again, only to have the whole thing erased from Buffy's memory in order to save the world. It is HEARTBREAKING.

Caroline in the City on Friends (1995)

In "The One With The Baby On The Bus" (Season 2, Episode 6) Caroline in the City's titular Caroline (Lea Thompson) stops for a chat with Joey and Chandler in the street. Chandler also made an appearance on Caroline in the City, which is pretty weird — for some reason we find Friends characters on other shows bizarre. It's inexplicable.

Seinfeld on Mad About You (1992)

This is great because it means Seinfeld and Friends are both in the same universe. In the Mad About You episode "The Apartment" (Season 1, Episode 8) Kramer turns up to be, you know, Kramer-y.

St. Elsewhere on Cheers (1985)

If you lived in the same world as the Boston bar Cheers, wouldn't you go there for a drink? That's exactly what happens in Cheers episode "St. Elsewhere" (Season 3, Episode 24) when some of the St. Elsewhere doctors turn up for a drink.

Everybody Love Raymond on The Nanny (1998)

[caption id="attachment_440870" align="aligncenter" width="615"] [Photo: Getty Images][/caption]In The Nanny episode "The Reunion Show" (Season 5, Episode 18) Ray Romano from Everybody Loves Raymond turns up as Fran Fine's old classmate at a high school reunion. Fun Fact: Ray Romano and Fran Drescher were actually classmates at the same high school in Queens!

Absolutely Fabulous on Roseanne (1996)

There's just too much brutal fabulosity happening here for us to be able to deal. In the Roseanne episode "Satan, Darling" (Season 9, Episode 7), Edina and Patsy from Absolutely Fabulous meet the Conners on their New York sojourn.

24 on The Simpsons (2007)

We told you Family Guy wasn't out favorite Simpsons crossover! That would be "24 Minutes" (Season 18, Episode 21), when Bart accidentally connects to Jack Bauer's cell, and obviously everything is hilarious.

[Photo Credit: ABC]