I like
![autism :autism:](http://www.intensitysquared.com/Smileys/default/autism1.png)
and
![Hamster wheel :hamsterwheel:](http://www.intensitysquared.com/Smileys/default/hamster.gif)
, because
![Hamster wheel :hamsterwheel:](http://www.intensitysquared.com/Smileys/default/hamster.gif)
was added after I complained about our lack of a hamster wheel smiley. I love the quick responsiveness of site management to important issues like the lack of certain smileys.
![Smiley :)](http://www.intensitysquared.com/Smileys/default/smiley.gif)
I have a few other favorites, but what I use depends on the nuances of a given situation.