Semi serious answer.
Bound to be more than this
The shorter the time frame the higher the risk you need to take, so …
Very short term
– Red or Black
Near medium term
– one or two low priced stocks – hope for price rise
Medium term
– one or two individual blue chip stocks, re-invest dividends
Long term
– some sort of stock market tracker
Very long term
– any fixed rate, low risk investment that returns higher than the rate of inflation – Gilts probably. Keep re-investing.
– buy property
Big risk that is unlikely to double the money
– buy premium bonds. You only risk the rate of inflation and it may never happen
– buy lottery tickets. you risk losing the lot and it’s unlikely to happen