My experience - Palitt Nvidia 9400GT w/passive cooling works like a charm.
Can others post here with what they have working in W7?
List so far:
8800GTS 512 (G92 core, note 8800GTS 320 & 640 have older core that doesn't support full HD acceleration)
TV Tuner Cards:
Nova 500-T (single tuner only due to W7 driver issue)
Nova T USB2 (Single DVB-T)
PC-TV 73e nanostick
HD 3200 (780G chipset)