Primecoin I'm not interested in. Not bothered about finding primes.
I agree with this. Prime Im not interested in. Computational resources could crack this and there is no market cap. PPC or peercoin is very interesting to me for the fact that it is a POW/POS hybrid. Bitcoin is a waste of electricity these days. Even with the Market for it because everybody and their brother is mining it.
Proof of Stake Coins are very interesting to me because transactions can be verified by matured coins. Coinage of 3 to 12 months. This actually reduces the need of verification of transactions through the POW or Proof of Work method. Although I believe POW is needed for fair mining POS blocks are good for coin holders to collect interest on their coins. Almost like a Savings Account.