If you're up for a bit of risk, seriously, root your phone. Long as you properly read & follow the instructions, and not descend into complete panic if something goes tits up, there really isn't that much of an issue.
My rooted Desire, running a ported Desire HD ROM, is still comfortably the best phone I've owned. I've got several Gameloft games, both iterations of Angry Birds, 3 different SatNav apps and about 2 dozen other apps installed and I don't have any space issues. Rooting rocks.