If you take sporting rides and are reasonably fit, 10 speed would seem to be the optimal number. Anybody for whom 11 and more speed would be useful wouldn't ask the way the OP does.
I think 10 speed is perhaps still a standard today? 11 and up is for more serious people who are able to ride reasonably fast, ride up serious hills, that sort of thing.
Anyway, there is not enough data supplied about the OP bike riding history, how he intends to use the bike, what sort of bike he is looking for etc. The more data supplied, the more useful the answers can be.