You want an analog to digital codec box. There are a number of different types of these, but my personal favorite are the ones that take in an analog (from VHS) signal and spit out a DV stream, so you can import video directly into iMovie, edit, then burn to a DVD with little loss of quality. I'd recommend the one I have, but it's an ANCIENT Sony box that they haven't made in years.
There are others that spit out an MPEG4 stream, I believe.
Some of the EyeTV probably do this, and some MiniDV cameras also have a "passthrough" feature which will act like a DV codec box--just plug your VCR into the video inputs, and your computer into the DV out, and you're ready to rip to computer.