what i really like to invest in is some real cryptocurrency that is actually focusing on acting as a decentralized currency like bitcoin does and has positive sides to it when you decide to use it.
but when it comes to reality i am never able to find something like that so i always stick with bitcoin because that is the real thing for me.
and then i focus on the altcoins only with pump and dumps in mind and only do it to make profit. so i look for the coins that have a better chance of getting pumped hard. these can be small coins or big coins but the important thing to look for is whether they are at the bottom or not.