well as far as the people using the Canopus cards go Strahlem, the raptor cards can also capture from tv sources. I haven't really tested them out myself (as not popular here) but I do hear from some people on another board about it.
The ADVC-100 looks good, but check with some others & if you can actually see it working at the shop before you buy.
Also check for driver support for your particular OS.
That was 1 of the big hurdles many go through with any capture card. How well it functions with win2K or winXP.
Am assuming ofcourse that not many are using win9x for these things (als better if you're on NTFS system).