I feed my guy crickets right now, but i want to give him worms too. And my local pet store only has those three worms so, which one is the best for my 5' beardie. And i will only give them to him three times a week.
by 5' I figure you mean 5 inches and not 5 feet right?
5' = 5 foot
5" = 5 inches.
If so, superworms are a no-go until your dragon is at least 16 inches in length.
Waxworms are the equivalent of feeding your children a hersheys bar,
And mealworms are crap to be blunt.
If you want to introduce worms and variety (which you should) you are best buying online. It's cheaper online anyways.
I believe that silkworms are the best worms to feed your pet. Silkworms are packed with nutrition and are great for all sized dragons! They may be a little bit expensive you when buy them live and a little more work than crickets or any other feeder, but well worth it. You can buy 250 eggs and the specific food you feed them for $20! Just have to do a little research about them first and read up on them. They grow very fast, but you can stop that and keep them at a desired size! I believe they go from egg to cocoon in 28 days. Which is 1 cm babies to up to 3 inches long in a month. Pretty incredible! Just my input