Saw your post in the anime thread, saw you've been watching some of the gambling ones. Good stuff, and all I've seen...I've been stuck, trying to find any more that may or may not suit my fancy. I agree--Zero is a bit weak, but that's because the schemes and games and puzzles...are kind of retarded, and juvenile.
If you are indeed looking for any more that may be fun to watch / read (since you've gotten to the best ones already), you might like Shoubushi Densetsu Tetsuya (Legendary Gambler Tetsuya)...I rather enjoyed the anime. Likewise, a good manga for you might be: Ten - Tenhōdōri No Kaidanji. Akagi is a main character in this manga...what this means is (since the Akagi anime stopped and the manga isn't quite scanlated) Akagi ends up surviving everything. Unfortunate spoiler that comes from knowledge of Ten, but it's a good read anyways.