For what it's worth, there are going to be a ton of biased answers in this thread. Everyone's going to have a horse in the race so just beware of that. Make sure to read white papers and understand the technology behind the coins that you choose to invest in.
Full disclosure, I'm invested in Siacoin and Golem. They're both pretty inexpensive and the tech behind both interest me a lot. Golem is essentially a distributed CPU while Siacoin is essentially a distributed cloud computer. Golem hasn't released much more than Brass Golem yet which allows the use of Blender over the Golem network. It's an exciting tech as it allows the ability to purchase processing power that can run tasks at a much faster clip than any single computer. On the downside, it is bottlenecked by bandwidth. I am really excited to see where it goes.
Siacoin is pretty self explanatory. People use cloud computing. I think it's fairly undervalued right now when compared with the estimates in value for Amazon's cloud storage valuation. Time will tell.
In addition, the BANCOR protocol is interesting to me. The ICO is this Sunday/Monday at 3:00AM pacific time. It theoretically allows liquidity of smart tokens on the Ethereum network. The ICO will be releasing at a rate of 100 tokens per Ethereum until it hits the cap or the ICO ends. Very risky, as is any ICO but if high risk is your game, it might be worth reading about.
Good luck to you, hope you find the right coins for your portfolio.