Are you using Haml?
If not, why? Seriously, take a moment to tell me in the comments. If you haven't had a chance to play with Haml yet, here is an easy opportunity to do so online.
All of Hashrocket's new projects are done in Haml, and we've now decided to transition everything else in our portfolio over to Haml as soon as possible. The indentation-based approach works wonders for generating clean, semantic markup and the way that you can see the structure of your markup in a way that easily maps to CSS rules is simply brilliant.
My initial impression of Haml was not as favorable. If you similarly gave Haml a try when it was originally released and couldn't get it to work in a stable fashion, you might want to try again.