Just to stick the cat amongst the pigeons... Why specifically an Android phone? Looked at the Windows Phone options?
It's too late and I've already got the Samsung on order but I'll entertain this.
My last contract phone was the HTC HD2. Everyone had warned me about Windows Mobile, but I'm not one to pay attention to any hype and I like to do my own research so I ignored them and gave it a go. While it was able to bare it, I ended up flashing to Android to make it my first Android device. Like Stu, I ended up using exclusively on Android.
This prompted me to get the Samsung Galaxy Tab as I wanted a proper Android gadget. However, in hindsight, it was a mistake to get it. It's basically just a big phone; too big to be a phone but too small to be a tablet.
So now I'm just going to do it properly, and get the Android device I can get right now. It's not really anything against Windows Mobile 7, I just don't fancy playing with it right now. I'm sure I can get a ROM to flash my HD2 to 7 if I really wanted a go though.
For the sake of giving this thread a conclusion the deal I got on the phone is £15 a month (12 month contract), £260 up front. 400 minutes, 1000 texts, 1GB data.