I like #region. Outlining stuff is ok (the already mentioned CTRL M/O rocks...), but the class explorer lists classes and methods alphabetically, not logically. It's easier for me to navigate a 1K+ line file compressed to a few lines which are logical/functional blocks like 'region IMyInterface members', 'region rendering', region 'helpers', then browsing through dozens of methods from a dropdown list given in an alphabetic order.Personally I don't like #region. I suggest moving away from the idea of the editor as the means of browsing your code, and coming to rely much more heavily on the class view (tab next to solution explorer) and the drop-down method quick jump list. VS2010 includes a huge number of options for discovering and navigating code. Free yourself from the editor 🙂.
And I guess I'm the opposite - I'd rather depend on something any decent editor with language syntax support should have (e.g. notepad++ supports #region), then on something dependent on a specific IDE. Not saying that one is right or wrong, just my personal preference...🙂