Challenging Courses

I have a ran a lot of races over the years and each course has been very unique and each person has their own opinion of the course. What I think is easy, someone else might thing is hard, etc. The last two races I have ran in have been pretty intense courses which got me to thinking "what has been the most challenging course"?  If I had to rate courses from the easiest to the most challenging I am sure that my opinion would vary significantly from someone else, but here it goes. My list of challenging courses, #1 being the most challenging.....

Tasha's list of "challenging" courses:
(1 being the most "challenging")

1. Go Girl 10K- Portland
2. Newman Lake 25K
3. Qualachan- Spokane
4. Spokane 1/2 Marathon- Spokane
5. Bloomsday 12K- Spokane
6. Helvetia 1/2 Marathon- Portland
7. Sundae Sunday 10 miles- Spokane
8. Boston Marathon- Boston
9. Colbert 1/2 Marathon- Spokane/Colbert
10. Cherry Picker's Trot 4 miles- Spokane/Mead
11. CDA 1/2 Marathon- CDA
12. Portland Marathon- Portland
13. Windermere 1/2 Marathon- Spokane
13. St. Paddy's 5 miles- Spokane (as you can see my list has already changed because I had to add Newman Lake)

** This list is subject to change and is based solely on my opinion**

--Tasha