Not all blog themes are created equal!
Most of the free blog themes are pretty good, some are better than others. Be aware that they may come with some limitations.
1. The person who wrote the theme might stop supporting it or upgrading it.
2. Not designed for the increasing mobile traffic to blogs.
3. Might not work the same with all the different browsers.
4. May not have the features for designing the site the way you want it to look.
5. It will almost always be outshone by people with premium or tailor designed themes and blogs.
In other words a free blog theme will mean you have to compromise in some way.
My favourite free themes for WordPress include Mystique (see Work From Home Wisdom Blog) and Organic which I used for the Leading & Developing High Performance blog.
Then there are the more commercial or premium blog themes that you can pay for. They often come with an option for a standard theme, only for use on one site, or a developer theme which allows you to use it for many sites. For this blog I use the the Genesis framework with the Agency Pro child theme.
I am very impressed with both the flexibility of this theme and the support you get when you come across something that baffles you. The team responds quickly and updates are made pretty frequently to add new features and to improve and develop the theme. I would highly recommend you have a look at them if you wish to have a professional looking flexible theme.
Other blog themes that I would recommend are WooThemes – Premium WordPress Templates. There’s some nice free themes here. The other ones you can buy as a single theme or pay for access to all of them. Some funky and contemporary designs too.
Of course once you have installed a blog theme you don’t have to stick with it. It is easy to install and preview different ones with your content and most theme sites have demos so you can get a feel for how your blog will look.
You might have to fiddle with your widgets if you do activate another theme and make sure you backup your site and database before you make the change.
Other People’s Choices for Best WordPress Blog Themes:
More WordPress themes than you can shake a stick at!
Blogger Themes for those of you that are tired of the default themes (there are only 16).
What’s your favourite blog theme?