Looking for a cool, quiet, stable under $100 video card with good Linux support. Hopefully will be able to run some games like Quake III decently, or Doom III at low settings, etc...

These chipsets seem to be in the under $100 range: ATi 9250, 9600SE, Nvidia 5200, and a few others like Volari, SiS, etc...

Thanks for your opinions.
Not even sure if Doom 3 and Quake 3 have support for Linux. But even if it did, those cards will hiccup when playing doom3.
The ATI 9250 is a passively cooled card which is puts out very little heat and no noise (unless you count air moving in your case passing over it). However, it is not very powerful for gaming and only supports DX 8.

The 9600SE and the 5200 are decent cheap'o cards but if your going to spend up to $100 (why else list $100?) you can do much better.

You can get Nvidia FX5500's and FX5700LE's for under $100. You can also pickup a 6200 for right under $100 though finding one in AGP might be a problem

On the ATI side, the full powered 9550 (instead of the 9600SE "special edition" which really means "we crippled the ram with only half the width to make it lots cheaper on us but not you edition") with 256MB of ram can be picked up for under $90. Even better the 9600 PRO and X600 PRO can both be picked up for under $100.

Starting at $100, I would lean you towards the 6200 if you want Nvidia (Newegg: Gigabyte 128MB/128bit version, make sure its not a turbo cache, for $99) or the X600 PRO (Newegg $99) if you want ATI. The X600 would perform faster than the 6200.

Dropping down from there, $80 your kinda stuck with the 9600SE from ATI or 5700SE from Nvidia. Both have crippled 64bit memory and cost about $75. The eVGA GeForce 5500 might be a better bet at $70, since it has a 128bit memory bus. Or the ATI Radeon 9550 (vanillia, not SE) for $66 (MSI version)

These are my picks out of all the stuff out there. If you would give me an ammount you would like to spend I can get more exact.
I'd go for nVidia, because of Linux driver support.