Horizontal drop down for primary navigation elements seems most intuitive to users in my experience. I think the most important thing is to keep common element

Horizontal drop down for primary navigation elements seems most intuitive to users in my experience. I think the most important thing is to keep common elements together and enduring - primary navigation elements (home, news, etc) and account option (sign in/out, edit, etc) should be separated and distinct, but they should always be visible and in the same place.