I went with the 75% choice. That may vary a bit depending on how you classify Paizo; with fewer short adventures by third party publishers, I rely on Dungeon magazine more than I used to.
Green Ronin, Malhavoc, and Necromancer historically put out great quality books that fit my gaming style better than Wizards often does. Complete Book of Eldritch Might, Hyperconscious, Beyond Countless Doorways, Book of the Righteous, Shaman's Handbook, Bow & Blade, the Advanced Race series (Green Ronin), Eldritch Sorcery, Rappan Athuk, Shades of Gray, Monsters of the Mind, and the Tome of Horrors series all play important roles in my game.
I find that my players principally use WotC stuff, and know little of third party materials, though I tried to educate them.

I even been known to pick up extra copies of third party books for my players if I can trade for it or get it on the cheap (frex, I picked up 4 copies of Masters of Arms at the Titan Games booth at gencon and distributed them amongst my players. It's a much more varied and balanced take on special weapon maneuvers than Book of Nine Swords.)
I consider early 3.5 a real dry spell. Third parties were putting out much more imaginative and fresh material while WotC was putting out the first 4 complete books, which were largely recycled, and had a mixed balance level (frex, WotC reprinted the weak sauce Geomancer which paled next to the 3.5 mystic theurge, but ENPublishing had already put out secrets of theurgy which gave some much more interesting and up to date prestige class concepts based on the idea of mixing arcane and divine magic.)
Third party books also provide more specialized needs than Wizards is capable of, it seems. I wanted a more general concept martial artist than the monk; Goodman Games gave me Beyond Monks. I wanted a fix to the ranger instead of creating "wannabe ranger" classes like the scout; FFG gave me Wildscape with the alternate ranger combat styles. I like psionics in my game, and find wizard's support insufficient; Malhavoc's Hyperconscious and Dreamscarred's Untapped Potential help fill that need. Planar support is largely provided by Ronin Arts, as well as Portals & Planes (FFG), Book of the Planes (Mongoose), Malhavoc's Beyond Countless Doorways (malhavoc) and Aasimar & Tiefling (Green Ronin).
Settings are a big place where third party publishers shine for me. I like making my own settings, but like some of the modular setting support I find in third party offerings. I don't want a monolithic setting like Eberron or FR. But I don't have the time to assemble my own settings from scratch like I used to. Fortunately, third party offerings have allowed me to assemble a world from my own tastes and inklings, and fill in the gaps with modular mini settings. Here is my world map:
As is partially conveyed by the map above, I assemble third party setting products like Bluffside, Freeport, Bard's Gate, Shades of Gray (Mayfarrow), Dry Lands: Empire of the Dragon Sands, Mindshadows (Naranjan), Sahasra, Hamunaptra, Wilderlands all into a world of my own making, allowing me the best of both worlds of freedom to create as a I will and built-in support.
Even among full-featured settings, I prefer the fresh angle of settings like Scarred Lands, Second World Sourcebook, and Oathbound to FR and Eberron.
I think if MMIV is any indication, the WotC monster well has run dry. Gladly, I have a slew of creative monster support in the form of the Tomes of Horrors, the Creature Collection, Denizens of Avadnu, as well as more topic-supporting books like Monsters of the Mind, and the "Lore" series by FFG, provide me with a great variety of innovative creatures to fit my taste.
I though I do find third party books more creative, I will say that there are some topics I am more conservative on that WotC fits the bill better for. For example, while I do use Mongoose's Seas of Blood as my principal seafaring resource, I like Stormwrack when it comes to seafaring skill use because I think it is a more appropriately conservative take on skills.
I also find that the (unfortunate) drawdown of third party publishers coupled with more creative and better books by WotC (like the last 3 completes) has me going to wizards more than I once did. But third party d20 products are still a mainstay in my game.
(Unfortunately, this has highlighted another advantage of third party publishers: availability in PDF. Most third party products I am interested in are distributed in PDF at reasonable prices, allowing me to do prep on my laptop upstairs or take it on the road. If I want to do prep with WotC books, I have to drag the books from my gaming library or make myself a gaming hermit, because I'm not about to pay full-printed price for a perishable DRM by Wizards, even where they do exist. Oh, and no, for those who might be thinking it, I don't download ripped off files.)