Until recently, game hunting has been fairly dry or if I do find something, the price is inflated. The local Goodwill has a bunch of PS2, PS3 and Wii games but mostly sports related or dirt common stuff like Uncharted and the like. They get some DS/3DS games but they are mostly the kid stuff. Anything older is rare to find. I haven't been to another thrift that's nearby that Goodwill in a while but there it's usually bare. Once I found a couple good Gamecube games (one was Legend of Zelda:Twilight Princess) but that was a blue moon affair. The Salvation Army downtown has had zip for years.
Where I live there are two thrifts: a St Vincent's and a place called Neat Repeats. The latter doesn't always have games, though when they do the price is usually right. The St Vinnys had games at good prices on a fairly regular basis until possibly someone there started checking eBay on collectible prices. Then there was a drought as more stuff was put online. Then after their remodel they put out a load of post 2000's titles but most of the prices were rather high for a donation shop. There was a Tony Hawk game on Xbox going for $12 which I've seen at game stores for less. After a while, more releases came out but more at the "thrift store" level as no one was buying. Hence probably why I got Contra for cheap. Right now their old stuff is out save for some GB snd GBC games.
My area could be going through a game collecting renaissance of sorts where buyers looking to flip have moved elsewhere or onto other things or people don't want to go through the eBay hassle.