Something like this is best to just be a poll as most of the people are just going to post which one they prefer. It be best if you made your first post something like "Which do you prfer Blackberry, iPhone, or Android? Give a reason on why you choosed the one in particular that you did too." It'll in that case be more fitting for a thread, plus it makes people give a bit more of a actual post. ^^
Don't argue with idiots because they will drag you down to their level and then beat you with experience.