There were two different large-disc video formats.
LaserDisc is probably what you are thinking of,
and it was indeed considerably better than VHS,
but in fact DVD is only marginally better than LD.
There is still a (small) market for LDs and players,
but they usually don't command much money any more.
If you are looking for a player, I would recommend
Pioneer or Denon over other brands, although there were
at least two Sony models that were pretty good.
Panasonic made one or two good models, but I don't know the numbers;
the rest of the Panasonic line had serious problems.
Some other companies, such as Mitsubishi, offered LD players for a short time.
In these, I would avoid anything I couldn't identify as being Pioneer-based.
Some older units carrying the Magnavox name may still be around,
and may even work, but they are huge and very heavy top-loaders,
so unless you have a rather large, strong table or shelf available,
these are best left to others.
The other large-disc format was CED (capacitive electronic disc).
It was a nightmare that (fortunately) caught only a few unwary buyers.
Its video quality was barely better than VHS.
These days, there are some people (including myself) who won't
carry a CED machine away from wherever it is, even if paid to do it.