I like the iPhone quite a bit. I need to spend more time with an Android device before I can say for sure which is my favorite, although I've always liked Apple products.
I've blackberry curve... actually its my new mobile... I like it alott... it actually works great for messaging (whatever it may be sms, mails, IM's, bbm etc)
I'm still attached to my Nexus One. I bought it the day it came out and have nothing but great things to say about it. I'll upgrade when a Google phone that has a quad-core processor comes out.
Sony ericsson used to design good looking phones, but I hate that everyone is trying to sell touch smartphones that are similar to iphones...