I'll second FOF1's comment about the EyeTV box for analog video capture. I just bought an EyeTV 250 Plus and I'm using it to convert a stack of old 8mm camcorder tapes - it uses a hardware renderer to convert straight to MPEG2. Not the best format for ease of editing (look at one of the Canopus or Pyro boxes to capture to DV if that's what you're looking for), but I wanted to get the tapes all into a format I could watch straight away on my PS3, and/or burn them straight to DVD without a rendering step (in theory, haven't tried that yet).
The EyeTV is producing 1GB MPEG2 files per hour of video, and in general I'm very pleased with the quality - much better than anything I've seen before from my experience using other analog capture cards on Windows boxes in the past (eg ATI All-In-Wonder cards).
Kevin