Picked up a bunch of cart-only NES commons from JJGames. I went the cheap route and tried to get games that writing/stickers on them. Though at least JJGames now shows pics of the carts you have in your shopping cart. So you can tell if a cart is un-cleanable. Found a $6 off promo code. So everything was only $50.10 shipped, not too bad really. Including the games below, I'll be at 281 unique carts.

720
Airwolf
Black Bass
Castlequest
Demon Sword
Fast Break
Gotcha
Gyruss
Heavy Shreddin'
Hogan's Alley
Hydlide
Iron Tank
Joust
Karate Champ
Klax
Lunar Pool
Milon's Secret Castle
Pro Wrestling
Racket Attack
Top Gun The Second Mission
Trojan
Ultimate Basketball
Wheel of Fortune