These are my personal picks as of Dec 17, 2017. I'm not recommending anyone invest in them, just showing my picks. I think bitcoin is stabilized to some extent by the futures investing. I'm not saying it won't still change by 20% in a week, but a lot of the smaller market cap 'aka altcoins' are moving by that much in a day or less. By spreading out my crypto portfolio, I worry less about the volatility. I am not 'day-trading' but also not all of these are long-term (1 yr/+) positions. I am re-balancing my portfolio regularly, so these positions are medium term I would say. I plan to hold them for one week to 1 year/plus depending, and re-balance my portfolio regularly so the percentage in USD that each one makes up of my portfolio doesn't get too far off my target.
My criteria basically are:

1. does it have unique utility? and
2. Is it investible right now?
   If a coin meets # 1 but not #2 I might consider, but not if it only meets #2 (ie I've stayed away from Dogecoin even though it has done well). Making gains on short term speculation is great, but my longer term outlook helps me sleep at night and if I think it has real utility / adoptability in the future, that helps. "is it investible right now?" for me means has adoption started or been announced? Are there big partnerships happening or in the works? Do others have reason to invest in it, meaning the supply -demand curve may push it up? etc.