I was working on a customer's Rails application this morning, and I was totally enjoying myself (Ruby + Rails + TextMate + Solr), and I was perfectly happy with my work and tools.
This afternoon, I was coding in Emacs + Slime + Gambit-C Scheme, finishing up the examples for a DevX article - once again perfectly happy with the tools that I was using.
A long time ago, my Dad (a great guy, great scientist, and member of the national academy of science) gave me some very good advice: enjoy whatever you are working on. It was a very long time ago, but I remember the context clearly: I was in high school, complaining about too much calculus homework, and my Dad gave me "the advice." By the way, I am taking a trip to see my parents next week :-)