The Juliana Hatfield Three did "President Garfield" about Henry Rollins (his real name is Henry Garfield).

Juliana Hatfield did a song called "Nirvana"

Sunny Day Real Estate had a song called "The shark's own private f***" which was about Nate Mendel being the "victim" of the "shark" Dave Grohl who got Nate and the drummer William Goldsmith to join the Foo Fighters after Sunny Day Real Estate broke up in the mid-90's. Nate didn't come back when William did so they wrote this song about it.

Neneh Cherry - "Buddy X" this song is about Lenny Kravitz cheating on Lisa Bonet while on tour when he supposedly was commited to Lisa. Neneh witnessed Lenny doing this 'cause Neneh was touring with Lenny.

REM - "wake up bomb" this is supposedly a dis at Oasis - one line Michael sings: "supersonic, what a joke"

Paul Westerberg - "world class fad" this was supposedly about Kurt Cobain. Paul said Kurt wouldn't speak to him when they crossed paths in a studio because Kurt was sure it was about him.