I would suggest you take the time to do plenty of research and look for Crypto companies that have real solutions to solve current problems. Many Alt coins have no product, just a promise of a product, and many of these companies will not survive the long term. Think back to the dot com boom when many new internet companies were hyped up have market capital of millions but never earned a cent and folded.
Personally, I still favor bitcoin among all. I still think that it has the msot potential and that it will still continue to grow so far. Its performace has been impressive over the years and many expect it to continue in the future.
But I agree that doing some research would really help you in determing what coins are best to invest in because by looking into its different aspects like the goal of the project would tell whether the coin would be a success. Most successful coins have very productive project designs.