Yes there are cards which you can input composite video and audio to and interface it to the computer. A friend of mine has recorded his home video tapes to DVD this way...I don't think my computers/hard drives are new enough to be up to the task though so I haven't done it personally.
Here is one that hooks up to the USB port (can't vouch for its performance but this gives you an idea of what is available)
http://www.costcentral.com/proddetai...13978/froogle/
I would really vote for the computer due to the much better control you have over the video such as editing/cueing it up before burning to DVD as opposed to a stand-alone device.
The best VCR's are probably older HI-Fi units that have been refurbished with new power supply components/mechanical parts as needed. Pretty much all new VCR's I have seen have been the cheap funai design.
Have you tried adjusting the channel buttons if present to adjust the tracking...some of these VCR's will override the auto tracking if a manual adjustment is made.