We've played a snot-ton of 6 Nimmt, so much that we've worn out two decks and are on our third...
I stopped by the Amigo booth at Origins this year and said that we play a lot of 6 Nimmt, and what would they suggest to diversify. They pointed me to 2Can and we played a round and I can see the potential, especially at player counts under 4 or 5. I haven't gotten it to the table yet at home, but it's on the agenda for July.