NXT!!
"But NXT can't be mined?" you ask... Well it can now,
https://nextcoin.org/index.php/topic,4388.msg41144.html#msg41144 -- indirectly. Why shouldn't you just keep your money in BTC or LTC?
When the Asset Exchange moves out of it's testing phase I personally believe the price will at-least double, to be honest it might quadruple in value as it has in the past. That is just short term growth, long term I honestly believe NXT will overtake Ripple in market-cap.
We have the best software (huge thanks to WesleyH), you can see a demo here
http://nxtra.org/nxt-client/, and it is becoming more and more user friendly (and secure) by the day.
NXT's feature's list is massive... Come on, we blow every other crypto-currency out of the water in that field. More features are being added weekly. A new currency has already been created on top of NXT called Nodecoin, it only took 150 lines of C++ to code (paraphrasing jl777).
There are a huge amount of people in our community that are working everyday to push NXT along.