Consider them in terms of "Generations". First of all 85% of all new coins out there are clones. Those are easy to dismiss based on how they are merely carbon copies of bitcoin/litecoin, only mess around with "transaction speed times", reward sizes, lottery blocks, etc - all gimmicks. Or the newer Doge coins/kat coins that try to play on memes.

Bitcoin and litecoin was first generation that uses a blockchain and wasted miner hash rates relying on hardware and electricity costs.

the 2nd generation are more like protoshares, nxt, emunies which have a far more complex wallet with built in exchanges, no "proof of work", instant transaction times, and a myriad of other features never seen before in the crypto world.

I personally recommend Emunies which is going to blow all other coins out of the water. It will be released here in a couple of weeks and was designed by the lead engineer at Google. I'm a beta tester and the wallet itself is amazing. Chat features, centralized identity with reputation, completely anonymous transactions, system is slightly inflation, system creates more emu's not on a set curve but based on demand for price stability so it can actually function as a currency, all the while not being under any centralized control as this is all done automatically.