I recently switched phones and providers, and I could have had my pick of basically any smart phone out there. I could have stuck with AT&T and got an iPhone, but I went with Windows Mobile-- specifically the Sprint (HTC) Touch Pro 2.
I was using AT&T and I decided that their network sucked and my "high-speed" data phone really did not achieve any kind of usable speed when I wanted to use it most. I remembered how Verizon always had great signal with their CDMA network, but they were way too expensive and their phones all sucked. So I went with Sprint (and what an awesome decision that was!). Sprint's network is leaps and bounds better than AT&T where I live-- I get EVDO speed in places I never even got an EDGE connection before. I actually have usable RDP over wireless now 3
Anyway, back to the phones. Sprint has Blackberries, WM phones, and the Palm Pre, among others. My wife went with the Pre and she loves it, and I sprung for the more mature hardware on the Touch Pro 2. Compared to the Pre, the keyboard and screen are simply amazing, not to mention the speaker is louder and clearer and the signal strength is better than the Pre. From a hardware perspective, the HTC TP2 stomps the Pre, the iPhone, the blackberries, and maybe even Nokia. This really is the finest piece of pocket-sized hardware I've ever used, bar none. The software may not be quite as slick as the competitors, and the app store doesn't exist yet, but overall I am VERY happy with this phone (with a bit of app envy).
Actually if they made this exact hardware configuration with Android OS on it, I would try it and probably like it even more. This phone is good IN SPITE OF Microsoft. HTC made the hardware, and HTC customized the software to make it tolerable, and Opera made a sick web browser for it. But I wouldn't count out the Windows Mobile platform just yet... I think MS is going to wise up soon. The app store is coming. They better get with the times, because if they don't, we will all be welcoming our HTC/Android overlords with open arms.