Some dogs I absolutely love, but know will never fit for me:

The Tosa-Inu(or tosa-ken), the Kuvasz, the Neopolitan Mastiff, the Fila Brasileiro, and the Karelian Bear Dog. I just know I'll never be up to being the type of master and providing the type of training, handling, and environment that I believe these dogs need to have to really thrive.

Some breeds I love that don't fit for me right now, but I believe can/will eventually include most of the other mastiff breeds I love.