Really interesting question, considering a lot of Hogan's best matches WERE at Wrestlemania.
I think xfear's mention of the Bossman-Hogan Cage Match is a great answer. That match was a lot of fun and really well done.
His match with Flair, also mentioned by xfear, was spectacular (the cage match for Flair's first retirement).
Hogan also had a great series of matches with Vader, with his best probably being their Strap Match at...I want to say Uncensored in 1995? Very good stuff.
Finally, Hogan also had a great match at an MSG show with "Mr. Perfect" Curt Hennig, a personal favorite of mine. This was a good match that really left Hogan's formula behind, with Perfect even derailing the Hulk Up, which was borderline unheard of at the time. Hennig won by DQ. It's on Youtube somewhere. Just a great all around match.