I'd have to back up every body's claim about Card Fighter Clash, I could not get enough of it. So much in fact, that I bought a second Neo-Geo Pocket and the other version of the game (I think I had the Capcom version, so I bought the SNK version as well) and tried to get every single card. Believe it or not, I got to 298 out of 300, and the only two I couldn't get were the ones that were randomly distributed when you played a link battle against another player. No matter what I did, I could never win the secret link battle card, and I kept playing over and over and over again. *sigh* Did anyone here every get all 300?
So for those of you who are not familiar with the game, but want to give it a shot, you will in fact encounter two versions of it, the SNK version and the Capcom version. The differences between the two are the same as the differences, say, between Pokemon Red and Blue (or Gold and Silver, Ruby and Saph., etc) in that each version contains a select set of cards that are unique to that version. There are 300 cards in all, but in order to come close to 300, you need to trade off with cards from the other version, which is not easy to do if the emulator doesn't have any kind of link support. Nevertheless, it's still a worthwhile play. There was a Japanese only sequel to the game, and someone actually started working on a translation patch for it, but really didn't finish the job. What's done makes it very playable if you're familiar with the first game and don't care about the story. And there's only one version of the second game, so I'm pretty sure you can get every card in that one, although I've never tried. I like the card artwork much more in the first one. There was even real packs of cards produced based on this game, and I have a few decks of them, they're extremely rare and hard to find.