Im finally gonna bite the bullet and buy a nVidia card for my system rather than relying on the onboard graphics. My problem is that im gonna buy one from ebay and dont want to shaft myself by getting something rubbish or incompatible. Is there a comprehensive list of nVidia cards my system is likely to be happy with that someone can point me towards?

The Dragon spec is an nVidia 6200 series, IIRC. That's plenty for HD. Try to get one that doesn't need a fan, with both VGA and DVI out if you're doing HD, or s-Video out if you're doing SD.
Of course, you'll have to see whether your MoBo accepts PCI-X, VGA or PCI, in order to know which type of card you need..... It matters! Choose wrong, and it won't fit. Not even with a hammer.

What about if i think i need something with a little more power. Could i safely use anything from the GeForce 6 or 7 series? I was thinking maybe if i was playing some fairly hardware intense emulated games, would i then need to get a more powerful graphics card?

I have found the following card.

http://www.ebuyer.com/customer/products ... uid=116473

Does anyone have an opinion on whether this card would be any good?

It's plenty for HD playback.
It would be helpful if we knew if HD is important to you, and what slots you have on the MoBo.

That's the card used in the Dragon from mythic.tv - http://mythic.tv/system_specs.php. I don't know about gaming, but my 6200LE works fine on my HDTV frontend...

My Nvidia 6200 LE card works perfectly as well for HDTV content.

Sorry to hijack, but will the 128MB Nvidia 5200 decode HD? Will not be watching while it records, but later

Not sure exactly what emulator you're planning on running, but you should check first to make sure that the emulator even cares about having accelerated graphics. MAME, for instance, doesn't use OpenGL or DirectX; it does its 3D rendering (for the games that have it) in software, in order to accurately emulate various 3D chips.

I think ePSXe only does it with some plugins that aren't normally part of the main branch (although maybe they've been incorporated).

Anyway, on a reasonably modern machine I can't imagine you really need beefy "gamer" graphics in order to play emulated games. It just smells a bit like overkill. But if you've got money to burn I don't think it'll hurt.

FTR, I have Nvidia FX5200s in both of my MythBoxes, both random house brands. Haven't tried HD yet but they seem to handle everything I've thrown at them fine.

Thanks, gonna give it a try once my sat card gets here