So the coins that are likely to succeed are those with:
1. Trusty developers. This is the most important one. Without trust, the coin is doomed. (check out this thread for POD ratings: https://bitcointalk.org/index.php?topic=568166.0)
2. Features. Does the coin offer something else than bitcoin? Does it have any unique features that makes it stand out? Does it have a solid roadmap for upcoming releases? Does the devs live up to their promises?
2. An active community. If noone has faith in the coin or is interested in it besides making quick money, it will never grow.
3. Marketing. To reach a bigger audience it needs marketing. This can be both from the devs or the community.
I chose my coin investments by those criterias. Trying to "game" the market and make a quick buck is just gambling, and it is mostely rigged by pump and dump groups.
I chose XST as my primary coin to invest in, but you may have your reasons and biases for choosing your investments. What is clear is that if bitcoin fails, for security or other reasons, altcoins will quickly become very very popular and only the most promising ones will be adopted.