Baltimore when Irsay packed up the Colts in the middle of the night and left for Indianapolis. St. Louis got screwed twice - once by the Cardinals, then again by the Rams. How about my Giants who left Yankee Stadium in the 70's to play at the Yale Bowl in New Haven, CT while the state of New Jersey built their new stadium? Then the Jets followed shortly afterwards.
I'm sure there are more but that's what I can recall without looking it up.
*MySmiley*
"Bustin' makes me feel good!"
Ghostbusters, by Ray Parker Jr.