I'm super excited about grin. All past altcoins have been just Bitcoin with a few bits tacked on; occasionally these extra bits are useful/interesting (eg. Monero or Ethereum), but in the vast majority of cases this extra stuff is just meaningless marketing-oriented garbage. But grin is packed full of useful innovation from top to bottom; moreover, it's clearly built in the same cypherpunk spirit that Bitcoin was: increased freedom/sovereignty through technology.