ETH and a couple of good ones like Stellar, Chainlink, etc. would be good. But ETH should be your biggest one there if we're not including Bitcoin in the list. Other avenues you can look at are IEO's, I've seen a lot of successful projects entering and getting out of IEO's and it really depends on what your interests are, I'm into gaming so I'm getting over this digital collectible project. So look for something that can still get your profits/ROI at the end of the day and at the same time, coins that you believe in and most passionate about.