Since you already have good coins, I suggest a new project probably started since last year and early this year.
DIA, POOLZ and CTSI has a great potential as of right now, and they managed to hit their new ATH at least for Poolz and CTSI. These are just my suggestions and you still need to do your own research before buying because its too risky to depend to anyone, so to prove that his is a good altcoin to buy please do your part.