Game Dude was the biggest one in LA area (North Hollywood).
They used to have a really good selection & decent prices (I bought a Duo for ~$59, Sega CD for $49 plus tons of "X" condition CD's which they sold off dirt cheap BITD, but that's all old news I'm sure)... I haven't been there in like 10 years though, so I dunno what the current prices are like.