For me, it is the media management that keeps me in the Apple ecosystem.
These types of features
Smart Playlists - Google/Android has nothing at present that will do these and I make HEAVY use of these.
Airplay - Love being able to start watching/listening to something on th go, get home, and then finish watching/playing on my ATV
Apple Remote - Again, being able to them control the content on the ATV/iTiunes from my iPad/iPhone is very useful.
iCloud - coming soon, but the ability to keep apps and data synced automatically between an iPHone and iPad is huge. It makes them not two separate devices but an extenstion of each other.
Also, backups - there is no easy way in Android to backup your phone, get your new phone, restore and be right back where you were on the old phone.
With the combination of all these you really are getting close to the holy grail of access to any media content, anywhere, anytime. Not 100% but getting close.
There is really nothing like the above in stock android. There are some 3rd party apps that attempt to do some of them, but in the end just about all still tie back into iTunes. Even the new google music service has no support for smart playlists at present.