I perfer LISP as a nice medium level lanuge, mainly for it's ability to modifiy it's own code as a data type. the problem is, is thier are few API's for it. at anyrate, for the most part I program in C++ but for as many things they did right in it, thier are quite a few things missing, namely, multiple returns.
as for a high level i don't know many, but C# seems pretty nice, however i am currently learning java which seems quite promising for atleast the deployment part of a application life style.
as for low level, G5 PPC ASM all the way, you can keep your 80x86.
