I love my Zune. The only people who hate them are iPod fanboys and there seems to be a lot of them. Look at it objectively and you'll see why Zune is superior:
Format flexibilty: Supports lossless WMA, Mp3, WAV and pretty much anything else you throw at it.
Wifi - sync wirelessly, send songs to friends wirelessly, download new songs wirelessly, multiplayer games.
Build quality - Zune's are generally very well built. The glass that protects the screen is very thick and scratch resistant. Also, I've not got dust under my screen and I've had my Zune for over a year.
Zune pass - download as many tracks as you like for a fixed fee a month and keep 10 of them forever. 'Nuff said.
Audio quality - obviously subjective but I've not found an Mp3 player that sounds better than Zune and I've been buying them since 1999. It sucks that there's no customisable EQ but apart from that its solid. The earphones you get with Zune are great at blocking out external sound too. In fact, they're better than some Shure earphones I bought recently for £40...