Ouray, CO is beautiful ( #18) and sits at around 8500ft elevation, so slow your breathing... lol!!! I did it in my Burb towing 7000lbs in 2002....NOT FUN!!!!
I've done #1 at least 10 times (maybe more) and believe it or not #2 in Switzerland and it was even on a Harley and it was awesome............If you've never been to Switzerland you just can't believe how green the hills are, absolutely amazing scenery