These days it's mainly Perl, a little C++ and Python, the latter of which I think would make a very good beginners language (even though it's actually very powerful) provided, as you said earlier, it has access to the RISC OS VDU commands. I haven't checked whether there's a library for that yet.
Maybe it's what I'm used to. I find myself wanting to use hash structures and linked lists. Before I started using other languages, I remember inventing all sorts of horrible hacks to try to implement even relatively simple data structures - the sort of thing I knock up in an instant if I need to keep my code more tidy and encapsulated.