For me, the music played as big a role as anything else for my "spots". One that I always went to again and again was 'The Crescent' in Brickstown. And I always had a soft spot for the iconic theme in AP.
In terms of visually pleasing spots to go, I have two, but they aren't spots in the most definitive sense. The first is Terra Volta - no real rhyme or reason, just had a thing for that zone. The second is "surfing" the rooftops in Steel Canyon w/ Super Jump. More often than not if I ever found myself with time to kill and nothing to do, I'd go to Steel, work my way to the tippy-tops of the buildings by window-ledge jumping, then surf the rooftops back and forth until something came up to pull me away from my aimless-but-very-much-aimed bouncing around. Just loved the view from up in the canopy of the urban jungle.