There are many wordpress web hosting providers, but in my view you can use any web hosting with Cpanel and auto script installer for your wordpress blog, there is nothing special in wordpress hostings.
Here is a list of best and top wordpress web hosting providers.
iPage (Not Recomended)
All hese web hostings are good and providing wordpress special packages, but in my view dont go with Ipgae, their panels are not good and features are not advance.
Asma thanks for sharing this list, Do you know Bluehost and Hostgator belongs to the same company. But Bluehost recommended by WordPress. Here is the detailed comparison of Bluehost and Hostgator.