I've personally been a fan of Pretend You're Xyzzy (http://www.pretendyoure.xyz/zy/) and CardCast (https://www.cardcastgame.com/) as far as online CAH goes. The design on PYX is.... modest, to say the least, but the custom decks feature is a killer app. Great for community games.
Really nice; The message half of the page covers part of the game part though, would be nice if you could resize it. Note this was on PH before here (before they had a separate games section) http://www.producthunt.com/tech/... It has changed a lot since the first version. Might be nice if the scores showed how many rounds the person has played too. Black card order doesn't seem to be randomized.
Was about to unfeature this because it looked like pirating, but it's actually fine since the original game was released under a Creative Commons license. Interesting!
RCRDList