VHS tapes have a finite life span (one of the reasons they became obsolete). I have several tapes that have degraded picture quality and color saturation and there is not much I can do about it. Over time the tapes become demagnetized and lose playbility.
With many of the tapes I have, I have put the ones with the least amount of degradation on DVD using a Sony RDR-VX560 that I bought from Tigerdirect for around $120. It is a one-click device. Load the Tape/DVD, and load a blank DVD/Tape and press either the record to Video or record to DVD button, and bingo. Go have a cup or 5 of coffee. If it is a two hour movie, it takes two hours to transfer. Remember that you will get VHS quality on a DVD record. Don't expect any improvement in video quality when transferring.
Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways,
totally worn out, shouting '...holy sh*t ....what a ride!'