Canonically none. As for speculation, Tai never was interested in Mimi. Joe, at least in the dub version, had a small crush on her, and Izzy was closer than most. But again, Mimi wasn't shown to be with anyone specific.
I always thought she should be with Matt, the секунда hottest. But since Sora ended up with Matt,( which is TOTALLY messed up,) I would think she would be better with Tai, the first hottest.
I do believe that she ended up with Michael, that blonde guy from America. In the epilogue, her child really looked like him and the Adventure 02, they looked pretty close, too.