Perhaps not unique, but a favorite of mine...
Ryan Rua of the Rangers signed a 11x14 for me and I asked him to add "First MLB Player from Lake Erie College," which he did.
LEC is in my hometown of Painesville, Ohio. It was a womens' college until the 1980s and only moved from NAIA to NCAA for sports in 2009. I went to their basketball camp in 1997. The school I attended from Pre-K through 8th grade was partnered with them for a long time before going independent, then when they merged with another school, LEC bought the buildings back in 2008 and uses them today for classrooms and a gym.