I think Batman Forever was the only movie I saw him in.
Despite my fondness for the band The Doors, I never really cared to see the movie. Not sure why.
That was unexpectedly pretty great. Granted, I haven't seen the last few of their April Fool's pranks, but generally they seem like they put about 0 thought and effort into them. This one looks like it took years to complete.
Things/topics that are common in Seinfeld but pretty much nowhere else on TV:
Dry cleaner's
Cuban cigars
Seriously, in the Seinfeld universe, way, way, WAY more people smoke Cuban cigars than cigarettes.