Solitude, cause it looks so [censored] badass, being carved into the mountain and all. http://www.gamingtarget.com/images/content/news/Skyrim_SolitudeMarsh_lg.jpg
i will definitely be building a multi level abandoned dwarven fort in the mountains near a stream sumwhere, might stay in the towns when im near by but my home base will be at my fort.
Please people, I beg you. Get your facts right, Stormcloaks=Solitude | Empire = Windhelm
Actually, you get the facts straight: http://uesp.net/wiki/Skyrim:Ulfric_Stormcloak Plus there is the leaked picture of the map at BGS that shows Windhelm circled and REBEL written next to it, and Solitude circled and EMPIRE next to it.
I'll have to wait and see. In Oblivion, Chorrol became my de facto home city, and I never spent much time anywhere else. I'm currently leaning towards Riften, though, for the interesting cultural mix.