If you're just boycotting Wizards, you may as well just buy some of the wealth of d20 products out there. You can even use your existing PHB - Wizards isn't getting subscription fees off it

.
For 'generic' d20 material, or stuff compatible with D&D, I reccomend, off the top of my head:
Green Ronin*
The Game Mechanics
RPG Objects
Devil's Workshop*
Goodman Games
Privateer Press
Malhavoc Press
Mongoose Publishing* will cheese you off to no end if typos get on your nerves, but their actual OGL games are excellent. Conan the RPG is very fun.
Finally, Paizo* is still putting out d20-compatible material, now able to draw on the much greater wealth of 3rd party stuff instead of being restricted to Wizards material.
* Companies marked with a * are ones I do or have worked with. Just so you know where I'm totally biased and self-interested.
If you're looking to explore a new system:
RuneQuest (the version I reccomend is also a Mongoose product, and it also has typos, but it's very fun)
Exalted (White Wolf's uber-high-fantasy campaign setting; less angst, more parrying thrown mountains)
Warhammer Fantasy Roleplay (a grittier fantasy RPG set in Games Workshop's wonderfully flavorful world)
HERO System (HERO Games' spectacular point-based system, great for the detail-oriented player)
Mutants & Masterminds (Green Ronin's supers offering, a sort of rules-lighter HERO)