Forum Moderators: Robert Charlton & goodroi
Stick to:
www.mysite.com/directory/
The problem with www.mysite.com/directory.html is that it's technology specific. If you were in the future to switch to say .asp, .jsp or .php (for example), then you'd find yourself either re-mapping the server or changing your URIs (which will lower your ranking).
There's no difference in the two when it comes to ranking weight, so think more towards what's best for your site and your users rather than the search engines.