8500's
Seems the 128mb models with bga ram OC pretty well. Mine does 315 without aritfacts and can handle 3dmark. Unfortunately I don't think I mounted the old pentium HSF on the gpu very well. It's about twice as tall as ATI's gpu cooler with much more surface area, but I can't get my core much above 290 without 3dmark "losing focus".
I use tweakmonster ramsinks (non-bga size) on the memory. I had volt-modded my previous OEM card with resistors and flashed it to the retail bios, but it slowly started to die, and in removing the resistors, I tore off a solder pad. d'oh! Luckily I was able to unscrupulously cover my handiwork and return the card for credit claiming a tragic cpu HSF accident had occurred. I did purchase quite a bit of hardware from the vendor in order to dull my guilt. And I'm pretty happy now with the 128mb model. Both of my 8500's had/have 3.6ns ram.