this is a no brainier asking that question here. ask it on the crackberry forums and you'll see mainly BB love.
i have a BB and i'm open minded of other devices but i love my keyboard. i have an ipod touch and that has curved my attention towards an iphone but not completely.
things i like about the ipod is the screen sice, fluid os and ease of use for most people. it is a simple phone if you want it to be.
the things i like about the blackberry are the battery life, messaging quickness and mostly the keyboard.
for me its usually the blackberry because the things i do on my phone are simple. bbm,text,call,google occasional addresses and phone numbers and use pandora. i know everyone is different and if you use your phone as a portable computer on the go then i would say iphone but if you just use your phone for the basics of staying in contact with people all day via text or email and leave the real web surfing for when you get home i would go for a blackberry.
there isnt 1 phone for everybody and you usually have to try it for a little while to find if it is right for you. asking on a forum just gives you a different user standpoint.