If you're a vaguely confident with one programming language and are looking for something a bit different - a little bit crazy, a little bit genius, a whole lot of fun - may I recommend:
If you're looking for something a bit more practical, again want to learn a new language, explore a bit about how a computer works, but also see how to build useful things (and beautiful things!) well, try:
If you're a vaguely confident with one programming language and are looking for something a bit different - a little bit crazy, a little bit genius, a whole lot of fun - may I recommend:
Land of Lisp
If you're looking for something a bit more practical, again want to learn a new language, explore a bit about how a computer works, but also see how to build useful things (and beautiful things!) well, try:
The Go Programming Language