Honest answer? Tiny apartments near massive, stable job creation locations bought during a recession. At larger scales, industrial real estate. And in my personal opinion, Bitcoin (very long-term). The rest is tricky and I personally try to stay away from other investments.

If you have money on the side that you can without then invest some amount and forget about it. Like deliciousowl has said, this is a very long-term investment that's about 50%-50% at the moment but with a huge potential well worth a risk in my opinion.

This doesn't have to be a big amount, but get some.

I think that real estate in strategic locations can be very profitable. You really have to do your homework on that one.

Bitcoin is in theory a good investment but I suppose we do not know what will happen.