I do not have much idea about waves but NEO can give you good returns. Many people say that it is a good choice for people who failed to make huge money as early adopters of bitcoins or ETH. It is also refereed to as Chinese ETH because of similar features and potential.
There are various practical reasons that make NEO valuable. For instance, NEO has support of big blockchain companies like Coindash. There are also rumors that even Alibaba is supporting this project.
I will also choose NEO. My stakes are also Cardano and Ethereum. meanwhile, I do not see any sense to hold them for 3 years. Probably, 2 years maximum.