Vid-card with TV-out connector like Ati Radeon vivo 64 or newer Radeon 8500.
They have TV-out and video in connectors so you can make AVIs or mpegs from your VHS-tapes if you want.
There are also GeForce2/3/4 cards with TV-out thought they usually have only TV-out and if you want one with video-in connector card is going to cost more.
I would buy Radeon 8500 myself. Now I'm using old Radeon 64vivo but when I connect VHS recorder to its tv-out the resolution is limited to 800*600. In Radeon 8500 you can use what ever resolution you want in your monitor and in your TV/VCR.