I've historically prefered 3Dfx, then nVidia then ATI.
3Dfx's drivers have always been solid. I still have my Voodoo 2 (Can't actually use it since Win2k+ doesn't have any V2 drivers...

).
nVidia's drivers have always been fairly stable and solid, and they do update them on a fairly regular basis. Their hardware has always leaned on the Crap side 'tho in terms of quality. They seem to just throw transistors at every problem. No once can deny their stuff has all the bells and whistles (Heck, they're the only card with the latest Pixel Shader engines), but the way they're designed feels so... inelegant. It's like writing a Notepad program in MFC vs WinAPI.
ATI sucked hard until the Radeon series came out. I was pretty amazed by that - Going from **** hardware and **** software to pretty darn good hardware and okay software

The softs have been getting better too (I guess they finally realised that they need to employ more than one guy to QA their drivers

), but IMHO still don't match nVidia's. And ATI do cheat as much as nVidia, they're just sneakier about it.
*Rant!*
But sod all that, I'm sticking with my Ti4600. I mean, does anybody not find it... I dunno... '****ed up' that a video card needs more power than any other component in the system?!
The Voodoo5 was bad enough - It was stupid then and it still is. But then nVidia go and trump them!
This thing about the 6800 needing two power connectors?! Has nobody else thought "WTF?!"
First of all, all Molex plugs are wired into the same originating points inside a PSU so unless the current draw is enough to melt the cables then you shouldn't need to plug 2 independant cables in!
And the fact that they also state that you can't plug any other components into those sockets apart from wussy crap like fans just scares the crap out of me!
If things keep on like this we'll need to buy a separate PSU to power the whole bloody card!
Jeez I can just see it...
"Intel announces a revision to the forthcoming BTX case specification, adding provision for 3 extra Power supplys to be added.
In other news, they have also revised the PCI-X to provide extra power rails for the more power-hungry PCI-X cards
(Insert picture of 2cm-thick copper tracks embedded in motherboard)"