If your only alternative to the iPhone is the Wildfire, I’d go for the iPhone… you will get frustrated, if you’re going for a HTC, In my experience; has to be Desire or upward… Had the HD- replaced a 3G and was duly replaced 2 weeks later by a 3GS, was great bar the awful battery life. If you can get a good deal on a Sensation (as above ^) or a Desire HD, even better, as shops are going to try and make room for the newer Sensation XE and formerly the HD, in anticipation of the Sensation. You’re bound to get a good deal if you shop aboot.
You can’t go far wrong with an iPhone, and as long as you don’t download ludicrous amounts of apps, it runs very smoothly. Only real downside being the lack of compatibility with the latest software, ie. from iOS4.3 upward 😕