“You’re confused.”
“I don’t think I am.”
Jay & Silent Bob Strike Back is chock full of people as caricatures of themselves, including:
James Van der Beek
Shannon Doherty
Jason Biggs
Wes Craven
Mark Hamill
Ben Affleck
Matt Damon
That was a smooth move, that cameo Howard Jarvis made in Airplane! Long after his name is forgotten, which it already is, people will still be seeing him since no one will ever tire of that movie.
Stephen Hawking on The Simpsons.
“Don’t worry, Lisa. Sometimes the smartest of us can be the most childish.”
“Even you?”
“No, not me. Never.”
I would do a thread about “Actors who were famous in your head for only one thing for decades, then you discovered they were actually famous as fuck”
But I can’t think of a better example then Jonathan Banks in Airplane! Didnt even know the guys name. He was just the dude who said, “He’s all over the place! What an asshole”
Decades later I find out that guy is fucking Jonathan Banks.
It’s been years since I’ve seen it, but I’m pretty sure he only appears onstage with Soundgarden and not in a speaking role (I may be wrong…I just looked up the wiki page for Singles and Cornell is credited separately from the band). A few other Seattle musicians get lines, like Eddie Vedder who I mentioned above, as well as Tad lead singer Tad Doyle.
Cornell has a little scene as someone who lives in the apartment building that Bridget Fonda and Matt Dillon live in. When Dillon installs the super powerful speakers in Fonda’s car, and it blows out her windows, Cornell is standing there with them.
Here’s the scene
Jonathan Banks is also the “muscle” in Beverly Hills Cop that kills Eddie Murphy’s friend, setting the plot in motion.
Thanks @Superdude. Now I remember seeing the scene. It must be twenty years since I’ve watched the movie, which was an absolute favorite when I was in university.
I think I’ve mentioned this elsewhere, but Banks was also a cold-blooded psycho killer on Hill Street Blues.
Matt Damon had a number of very funny cameos on Entourage playing an intense version of himself:
Similarly Damon’s ongoing feud with Jimmy Kimmel.
Buster Keaton in Sunset Boulevard.
Toward the end of Parks and Recreation’s run, Leslie Knope goes to Washington and meets with several real-life politicians who have cameos. My favorite is Joe and Jill Biden.
You mean the one mentioned in the OP?
Um, yeah. Now that you mention it. 
Bert Parks in The Freshman (1990)
Carrie Fisher in Maps to the Stars.
Did anyone mention Bob Hope in Spies Like Us?
It’s probably obvious to all of you that Big Bang Theory deserves special mention in a thread like this. I say this because there were so many more cameos than those mentioned upthread. Without knowing for sure (or really caring, either), I’d say no other show has had so many.