DinkyDana is really good as well.
If you like flea market finds, check out Pat The Nes Punk. He has a series called Flea Market Madness. It is really good. ALso, there is a channel called Captain8bit. They make a show called game chasers. It's really good as well.
I agree that finding all the N64 games boxed in thrift stores is hard to believe. One thing in favor of it is that the N64 is not a huge library. It's been out for almost 20 years. If the user has been at it seriously for 20 years and lives in a bigger city, maybe. But very doubtful. It wouldn't even make much sense to just limit oneself to thrift stores. Ebay can honestly give good deals on some games. Madden Football 64 recently sold for 99 cents CIB on ebay. Why waste gas getting to the thrift store for that one?