The Panasonic DMR-ES10 is a consumer DVD recorder that is reputably very good at dealing with unstable or low-quality VHS sources. I've seen a fair number of people say they use it as a pre-processor for captures (i.e. in "pass-through" mode, not recording to DVD).
Edit: interesting discussion here:
http://www.avsforum.com/t/1252109/panasonic-fans-vhs-conversion-lsi-vs-inhouse-es10-passthru-dmr-eh50-vs-others