I would suggest the coins that will be listed on Coinbase. These are more likely to get better in the long term. Or you can always invest in ICOs, just make sure you pick the ones that will do well in the future or may be used by the masses.
That's definitely a good advice, picking coins for long-term/short-term investment is really difficult because one mistake will lead to huge losses in the future. Coinsbase is a good wallet/exchanger and has a good reputation when it comes to cryptocurrency trading/market wherein they have a huge variety of realiable coins so you just have to choose the best suit to them.