The hard thing about either removing or painting paneling is that it is so "final".
Personally, I like many of the lighter colored, high-quality paneled walls that I have seen.
But I've studied it as completely as I can and, as a Realtor, I am stuck with the facts. There are exceptions of course, even "miracles" but if you want to sell your house as quickly as possible at the highest possible price, remove the paneling and replace it with drywall if it's in the entry or main living area. It's really rather inexpensive if you are able to do it yourself. At the least, paint it.
But if it is in a basement, is a lighter color and is pretty nice quality, it might not hurt the sale too much. It still won't be a plus, though.