The original, factory Yamaha patches are some of the best.. they have several banks so I'd download those first,
Also, my good online friend Yoozer a few months ago pointed to this - Hypra patches:
The Legendary DX7 Hypra-ROM Cartridge - Harmony Central Musician Community Forums
I have to say the Hypra is one of the very best (if not
the best) DX7 patch compilations out there.