I use a HTC Wildfire S and it isn't bad, but getting ropey Internet on Orange. And still getting used to the touchscreen, keep mis-pressing it.
Android all the way!
You could even get the older HTC HD2 (around £150 ebay/ £185 new if you look around).
Ok, comes with WinMob 6.5, but you can root it and have WinMob 7 or Android 2.3.4 (and you can even dual boot it between the 2 ;))
I've the ZTE Blade (Orange San Francisco with 2.3.4), and did install Android 3.0 on it a few months back but the screen res was so high you couldn't really use it!