My favorite things about windows phone are 1) quick searching, 2) integration of the people hub, and 3) integration with windows and office.
1) with searching I can typically find anything faster than my wife on her galaxy S4. From anywhere on the phone I can get to a barcode scanner, local dining and things to do, and a music identifier in two or three clicks.
2) the people hub combines everything from twitter, Facebook, email, text, and phone in one place. I can see everything about a contact in the one history screen.
3) every contact and email I send or receive on my phone syncs with my outlook account. The same with my documents edited in office show up in my recent files on my computer's office. Contacts are, by default, outlook contacts so that even of my phone is dead or I can't find it everything is in my outlook.