I'm not going to list a top five but I'd like to see our now apps updated to par of other OS' (facebook, twitter, instagram, tumblr, myfitnesspal is my biggest gripe in this category)
I'd also like to see more banking apps, my bank does not support windows phone and ill harsh there tech support every few months about it.
And next are the facebook games (candy crush) not for myself, but for all those out here that want those my play trend games.
Next is more smartwatch support (I know Bluetooth limitations are the main issue behind this but come on soon please.) I'm dying to get a pebble or fitbit. Even gshock has a Bluetooth watch I'd love to purchase.
My main issue is that big name developer are still holding out on us for the most part and wait for microsoft/nokia to throw money at them. Thank godness for people like Rudy Hyun. (sorry if I misspelled the last name)