Phone: iOS 7 because of the lack of stripes.
Passbook: iOS 6
Mail: iOS 6
Photos: iOS 6 tough call though.
Facetime: iOs 7
safari: iOS 6 by a long shot
Maps: iOS 7 (one of the few new icons I really like
Notes: iOS 7
Stocks: iOS 7 (pretty good icon)
App Store: iOS 6 (because the circle is smaller and that makes it look more harmoneous)
Weather: I'd say draw. Both are pretty bad though
Clock: iOS 6
Reminders: iOS 6 (these neon colours...)
Newsstand: iOS 6 (I like neither but the new one is just off limits ugly)
Music: iOS 6 clear winner
Vidoes: iOS 6 (that gradient on the 7.... )
Messages: Draw to me both have their weaknesses.
Game Center: iOS 7 (though the icon makes no sense to me)
Contacts iOS 6
Compass: iOs 7 by far.
Camera: iOS 6
Calculator: iOS 6
Calendar: iOS 6 (just because its so much easier to read)
iTunes: iOS 6
Overall: iOS 6 vs 7: 15:7