I agree. High quality board-game apps seem to be the biggest gap on android tablets. I love Elder Sign: Omens https://play.google.com/store/apps/details?id=com.fantasyfli... but that's the only one I've found to be really high quality. Carcasonne and Catan aren't as good as their ios equivalents.
While I'm plugging tablet board game apps, this implementation of backgammon is Awesome. https://play.google.com/store/apps/details?id=com.njsoftware... It regularly wipes the floor with me on higher difficulty levels, and has a lot of really nice features.
Scrabble on iPad is awesome. Also, please dont mention Words With Friends.