You can cycle through the three different modes using the Ctrl + Page Up and Ctrl + Page Down keys.
If you want your pages to open in a different view than Markup View, choose Tools Options. Then expand HTML Designer, and in the General category, set your preferred view. Alternatively, enter HTML Designer General in the Quick Launch text box (which you can access by pressing Ctrl + Q) at the top-right of VS and then click the item in the list that appears.