To test this I have created my blog in all three popular sites and so far I am a fan of www.Wordpress.com
You can go to my each blog and decide which is the best.
https://prasanthtech.wordpress.com - The setup was a breeze. There are quite a few themes and the whole thing can be customized quite a bit infact more than 25 themes are available and even then you can customize easily. And you can even imports your postings from other blogs like blogger.com which I did and went without any hiccups. Which is really nice. So now I am sticking to this as my main blog and let the other stagnate. To get an account yourself go here www.wordpress.com
prasanthtech.blogspot.com - Its fine but you cannot upload picture which is a big let down for me. Since Google runs www.blogger.com you can make money by putting ads etc on the site which is nice. The webpage looks okay.
http://prasanthtech.spaces.live.com/ - This is really shit. You have to have a Hotmail account and the pages are really bad looking no way to customize and ad's are so big etc. The worst of them I tried. Still if you want to get an account here here you go http://spaces.live.com/