It's will vary to each people.Some may suggest Ethereum and some may suggest other. But in the current market ,you can't get 4 or 6 times of profit now.It will take huge time to get 4 times of invested money.And altcoin is the best one for the long term profit.If you look altcoin for short term profit, it's not possible.
You absolutely right Please sir I need to contact you via email
My mail wordornakpordzidzor@gmail.com
I have an offer