I personally use the Sabrent VD-GRBR and have never had a problem with it. Magix also sells one, but you should be able to go to a local electronics store and ask to have a look at Video Capture devices. Don't get anything too expensive, but if you have sVHS on your machine make sure the device can hand s video.
And don't go cheap either - some of the cheap USB video converters just pass the audio through to the sound card and rely on this for capturing the audio - you can recognise these because they have an extra audio connection/lead to plug into the sound card.
This type can give you sync or echo problems depending on your sound card type.