Which is the best 1st generation smartphone??

For sometime now I have been carrying two smartphones with me, thanks to me being a Mobile Developer. Till yesterday there was a HTC Mozart(Windows Phone 7) and a Nexus One (Android Froyo), but today I had to swap my Nexus One for a iPhone 2G(iOS 3.1.3). While playing around with these phones, I realized both the iPhone and Mozart are first generation phones of their respective platforms. In that aspect, I have also used HTC Dream (G1, Android) for quite sometime. So the thought came to my mind, Amongst the 3 first generation phones, which is the best?

Before going into my opinion let me tell you that, I have traditionally been a Microsoft fanboy, and an Android lover, and a bit of Apple hater ;). But I will try to be fair on my judgement. 
The iPhone2G is a first generation phone in terms of hardware, the OS is not. My 2G is running iOS3.1.3 which is almost 2-3 years younger than the rig. Also, it has a million+ apps base now backing it. But to even this advantage out, the 3 year old phone is compared with a new Phone that was launched few months ago, and another a little earlier.

User Interface 
iPhone has a child-like user interface with embossed, glossy icons placed on a low screen resolution display, though many people say it is very intuitive and simple. 
Windows Phone has an unbelievable and revolutionary user interface. Everything looks so aesthetic, and eye pleasing. Giving much importance to the actual content than Chrome, you hardly see the phone OS, you see exactly what you are looking for. Be it your phone book, or your tweets.
The HTC G1 has a very barebone user interface. And it feels like using Windows 3.1, in terms of the styling and theming, it is definitely not the most beautiful designs I have seen. It gives you most of the things you want though, in terms features.
Verdict: WP7 beats iPhone by a few miles and Android by a few light years.

Usability
As mentioned before, this is about the software, so technically iPhone has a little advantage. But still, it lacks multi-tasking, and looks more or less basic. I still get mails delivered in the background and my tweets pushed through notifications, so it is very much usable. 
Windows Phone 7 fails here miserably. It starts with the lack of multitasking, similar to the iPhone it fetches your mails though.There is no push notification support, no sockets (no chatting), a poor browser (limited HTML5 support) and (hence?) pretty limited apps.
Android scores a home run here. It gives you everything you can think of. You can run a plethora of apps in the background (in the 70MB available memory), be available on chat all the time, receive tweets, and anything you could actually do in an computer.
Verdict: Android pays back Windows Phone,and iPhone stays where it was.

Stability
The iPhone I have is already 2+ years old, with a broken glass and is jailbroken (multiple times), but still is rock solid. No app has ever crashed while I was using it (you can't know if it crashed, even if it actually did :] ). 
Windows Phone has to catch up here. Few of my apps have crashed multiple times ( eg: Foursquare) and my phone itself crashed once and I had to hard reset it.
Android was worser, I used to get "Force close" messages and numerous crashes regularly. Maybe I am biased here, as I used to develop apps and run them on the phone :) Moreover the I could run any spurious app I want, on the phone, with no app restrictions in place.

Apps
Apps have been iPhone's forte and it will be, at least for some (more) time. Only that many of the apps have evolved and ignores the 2G phone now.:)
Windows Phone has some good apps, and generally they have kept the quality of apps high. Also, every app has a "try" option which is good. I haven't seen gaming experience get any better than the XBox live hub in my Windows Phone.
Android again has had a different approach, you can find all sorts of apps; good, bad, harmful, crappy and what not. It was hard to find quality apps in the platform, though there were a few.
Verdict: App-le it is, followed by Windows Phone and Android.

I can't say which is the best first generation phone, each one of them have been exciting in their own ways, if it was the fresh User Interface in the Windows Phone, iPhone brought about the touch phone revolution itself. Android took smartphones closer to computers and gave me infinite possibilities. 

But, if a G1, Mozart and iPhone was kept in front of me and I had to pick one, I would have probably picked the G1, er.. no... the Windows Phone..oh..or is ..it ... the iPhone?

Send in your choices. Which one would be your pick?

PS: I really miss my Nexus One. It is a hell of a phone!