I am trying to remember the name of the two booths at Gen Con that have the used RPGs. 

One has the long rows of book shelves with games you can purchase multiple and then get some free. Lots of Palladium, L5R, etc at discount.

The other is a game store that brings in old AD&D modules, box sets, and collectibles. They are all on tall tables with boxes organized by D&D worlds, etc. 

Games Plus+  Booth 1841 has lots of gently used RPGs.

The other might be Cool Stuff Inc 1501-1511

Troll and Toad (Booth 1201) also has lots of used games.

One has the long rows of book shelves with games you can purchase multiple and then get some free. Lots of Palladium, L5R, etc at discount.

Sounds like Chimera Hobby Shop.  They're on the map for booth 2301.

It strikes me as particularly interesting that, despite having seen them every year for who knows how long and I think even done the buy-one-get-three-free deal before, I would never in a million years have come up with "Chimera Hobby Shop."  I do not even know what I thought that booth was.  I conflated it with Crazy Egor's, and even though I knew Crazy Egor's was long gone, I never updated that place to be unaffiliated with Crazy Egor's, haha.

I feel ya. Why do you think I was asking. I stop by both booths every year and was just drawing a blank while planning for this year.