Well, technically there is no "windows standard" TV tuner card. In fact, a MCE computer doesn't even *have* to come with a TV tuner to be called a MCE computer. But essentially all do.

Manufacturers will end up using any particular TV tuner card they want... could be an ATI or ATI-based one, could be something else. It all depends on the particular PC, but mass manufacturers like Dell, HP or Gateway aren't likely to tell you beforehand so you sort of get what you get and if you don't like it, upgrade! :-)

With that said I'm running a home-built MCE2005 PC with an ATI TV Wonder Elite, which is based on the Theater 550 Pro chipset with hardware encoding (you really do want a card with hardware encoding) and so far I'm fairly happy. I do wish the TV quality was better, but reportedly this is as good as it gets.