I mostly hold Dash, but I'm very interested in the progress of "beyond currency"-applications of blockchains, that's why I delved into Factom and Maidsafe as well. I hope the latter soon becomes more than vaporware. The fundamental ideas of both these projects convinced me (Ethereum still needs to settle its actual place in the world and declare what it wants to be imo, hype doesn't convince me, even though I made some profits with it). Of course this isn't investment advice, because in any case: Due diligence is key.
RE: Best Altcoin to Invest In?