All of them work just fine. I had a "hiccup" with Mountain King that I had to replace, and the original cart purchased was refunded.
I'm waiting for MONTEZUMA'S REVENGE to arrive, so that'll bring me up to 22 carts. I recently acquired DONKEY KONG for the 5200, and, as both a 5200 and a ColecoVision, the homebrew 5200 reigns supreme for a multitude of reasons and observations.
Here is my original post when I joined this community. Lots of fun, and the condition of the 5200 that I got is more or less brand new (I lucked out on that one!!!) Additionally, I've been very, VERY CAREFUL to purchase carts, the trak-ball, and whatnot for this system that are in pristine condition. Look at the condition this 5200 is in (in the quoted thread below). I've never seen ONE 5200 that looks this good on eBay, Amazon, or if you want to sell your soul, HELL.
It is a privilege to be a part of this community. While I've not been here in quite some time, I intend to stick around, and hope to make some good friends. Ok, so, I'll shut my trap and let you cats have a say.