I really enjoy Ruby. It has the definite feel of a language developed from the beginning to be object oriented. Now that I've looked a little at Smalltalk, I can see a lot of similarities in how it does things. It's nice.
losers graphs – didn't end up using this (excel instead), but interesting, nonetheless. In particular, it gives some good examples of Gruff graphing as well as an interesting example of Hash#sort_by