I don't think anything can beat self hosted WP. They also have great templates that would turn your blog into a beauty
In my opinion, every blog is helpful and useful,If your content or post is great,your blog is excellent.
In my opinon every blog is not helpful i think only do follow blog is helping in your site ranking in your traffic . Thanks abhi
I prefer blogspot since it allows me to set up adsense. But from what I know, wordpress is perfect if you want to have a professional looking site.
start with Wordpress.com and when you feel u ahve enough popularity, get a self-hosted wordpress.org blog