Just from personal experience, I think you'll have better luck with Hauppauge and Avermedia cards. Because they're TV tuner cards, though (and TV tuner drivers are almost always hit and miss), I would recommend playing it safe and going for "Windows 7 Certified" cards. That's not always a guarantee, however, so you obviously want to scour over reviews too.
You also need to decide what would be best - an internal device (i.e. PCI card, PCI-E card), or an external device (i.e. USB).
I got my ancient ATI TV Wonder (PCI, original initial version, not 650, 550, Pro or USB etc...) working great under 7. So I probably correctly assume all ATI capture cards, any gen, are good.
I use iuVCR and/or VirtualVCR. Both are really good and never drop any frames even stressed. If I were you, I'd look for an HD version. I think they have them now.