If I saw someone with, say, a full PlayStation collection, you know it would be 98% shit and most games were bought for pennies in bulk. Not impressive. Seeing a full Virtual Boy collection or something like Wonderswan would be impressive. Things like that take at least some dedication.

I personally only keep playable games. Also, to curb my obsessive nature, I enforce a strict first-party rule for my GBA/DS/Wii games. Sure, this causes me to miss out on some good third-party games, but I don't have time to play the games I already have. My PlayStation collection is pared down to only the finest games as well, totaling around 45 games.