My top almost 10:
1. Discussions
2. Local User Group
3. Support [Specifically My Cases]
4. Product Docs
5. Super Secret Group
6. Events
7. Blogs
8. Partners
9. Find Marketo Experts
10. Products
As a note I use the first five about 85% of the time while 6 - 10 I'll check occasionally. If I was just starting out I would include University somewhere in my Top 5.
I'm not sure I have a preference of order, but I do think that the "support" system could be a bit easier to navigate. Right now it takes 3 clicks to submit a case, even though I click "support" and then "create a case" ... I still have to click "create a case" one more time on the next page in order to actually submit a new case.