If your methodology for identifying "cities with nice weather" returns Reykjavik in its top ten, either your sample only includes places with terrible weather, or your methodology is completely whacked. Reykjavik is a wonderful little city, but it's cold, extremely windy, and often very miserable. The place with the most pleasant weather I've ever experienced is probably the area around the Gold Coast, Queensland, Au…
My personal preference is definitely for colder temperatures than most other people would like. I didn't include humidity, precipitation, wind, etc., mostly because I threw this together in an hour or so and didn't intend for it to be a "serious" analysis, just a novelty.
You should really check out San Francisco...