Depends on what your goal is.  If you want to be highly speculative pick one that has not hit an exchange yet such as Stablecoin.  If you are looking for something a bit more established then Feathercoin is probably the best option.  Digitalcoin seems like a good balance between the two.  The key is also choosing something that has active developer support.  All of these have this at the moment.  Memecoin is another one with a very active developer however the market for it is still relatively small.  A good place to start would be coinchoose.com or coinwarz.com  But understand that you shouldn't pick a coin based on the instantaneous profitability these sites spit out.  Other decisions that need to be factored in are market volume, price stability/trends and network stability.