BASIC

So I asked /g/, but of course no one on /g/ actually cares about programming.

What sort of features might a good BASIC have?

My two personal favorite languages are Lisp and Go, I just wanted to ask a hypothetical question, in that, I think it would be neat for there to be a fresh and cruft-free BASIC for people to toy with, and where better to get input for features a good BASIC might have than strangers on forums?