There are a lot of promising altcoins that you can invest in, and will make huge returns, you just have to be willing to do your research. If you continue to ask people, they will just shill their own coins for you. It's better you do your own research.
I will advise you to research some altcoins that did very well during the previous bullrun but their prices are presently low now because of the bear market. And you should invest in them, they will go high than their all time high at the top of the market.