I support your IE stylesheet ban. CSS can definitely be written without a separate IE CSS and be pixel perfect across browsers. Several techniques I've incorporated to help avoid browser inconsistencies:
Use a good clearfix.
Avoid margins and use padding instead as much as possible to avoid issues with margin collapse.
Be weary of inline-block.
Use a good clearfix. Avoid margins and use padding instead as much as possible to avoid issues with margin collapse. Be weary of inline-block.