I'm big on smartphones. I've been using them for a few years now, and as I'm pretty much poor I've been buying used ones. This has the side effect of them breaking in some fashon after a short time, with the upshot that I get to use a lot of cell phones.
I have owned (in this order):
HTC Touch Pro
HTC Touch Diamond
HTC Touch Pro II
Now, HTC generally makes pretty good phones for power users, but I found that they're a bit overkill for someone who wants a phone with good sound quality, long-lasting battery, and things like that.
When I got my Nokia, on the other hand, even though it's an ancient Symbian-based blackberry-style phone, it still gets 4 to 5 days on a battery (moderate use), has AMAZING call quality on T-Mobile, and the keyboard is more than usable (I'm writing a fanfiction that so far is 10,000 words, all written on this cell phone).
If you'd like, I've written up a more comprehensive review of the phone detailing my experiences with it, and after using other Nokia devices I'm pretty sure the basic idea of this article applies to most Nokia phones.
You can read the article here (clicky)