For me, there are a few things..
1. Google - Look at the speed of development of Google apps on Android (e.g. Maps & Navigation). Google can "relax" development on the iPhone whilst going crazy on Android. Given Google is probably the most important "data store" for many mobile users (maps, google search etc), myself included, and I think Google are more powerful than Apple, I'd rather side with Google.
2. Choice - with Android you have multiple handset choices, wether you want a super fast one with a big screen, or a budget one. Regardless, you can still run Android very well. Apple, meanwhile, you have to purchase a phone which costs more than a fairly top end laptop, despite the hardware hardly being superior compared to a top end Android phone at significantly less
3. Control - I do not like the way Apple locks you in, apps must be approved by them, you cant try another system app (eg browser) because Steve Jobs said so. I don't like their "closed in" culture, why can't I customise a home screen? I want to unlock my phone, see the clock, weather, latest news headlines etc without spending ages refreshing apps and what not.
Things that Android needs to do better - music and better apps. However, it's fairly clear, as you can see, all the big companies realise the need to make apps for Android now.
