I'm a gadget freak and have used lot of phones and have come across a lot. In my opinion, I think Sony Ericsson is the best when it comes to feature and prices-wise.
Nokia has been the world's best because of their good marketing. So you might find it easier to find its applications on the Internet.
Any time you compair a Nokia and Sony Ericsson of the same capacity you'll come to see that Sony Ericsson is always ahead of Nokia, either price-wise or feature-wise. Anyone want to prove me wrong?