Blogging makes a great tool to market your business. Many free and paid services are available. I'm going to weigh in on my opinion based on observation and use of the tools.
Blogger -- I obviously prefer Blogger. I use it for this blog, and I have been satisfied with its capabilities for what I do. And that is key to the process. What are you going to do with it? Now video blogging has become a big deal, and many marketers have promoted its use as popular. I see many sites now use video blogging, too. For what I do, video blogging isn't key. So my use of the video feature isn't as critical. Most sites now offer that feature (more or less in capability). Blogger allows you to insert a video. The problem I found is that my iPhone capabilities make it nearly impossible to send a video to my computer (too much bandwidth is required). So if you do intend to video blog, it's more dependent on whether or not you have the video-making capabilities. Additionally, some blogs have the same restrictions on how long the video can be. Blogger does allow image insertion, which I do use. What I really like about Blogger is how you can add the story feature (to the right) that sorts stories by popularity. I think it adds an attractive and interesting capability to pull more readership for those stories. Comments can also be moderated and/or eliminated if they are inappropriate, and spam can be controlled. It connects to my social media. And of course like all blogs it features dynamic update.
Typepad -- this is a PAID service. I use it for one of my clients. It does more or less than Blogger. Its key difference is its connection to Technorati (a keyword service). I think it costs $19.95 a month (not sure though, because I don't pay for it). It also provides suggestion on keywords and/or connections to older posts (I like this). I'm not thrilled with the image feature that is a bit of a pain. And it offers conversion and uncovers code so programming types can play with it. Sometimes the programming pops up anyway, and I don't care for it. It does provide a great sorting features and categories you can self-create. This segments your blog and helps readers find specific topics under those categories like a table of contents.
Tumblr -- I have used Tumblr, which is the social media site of blogs. People follow you to read your blog. This service is free, but vastly different in how it acts like social media. Tumblr is known for its video capabilities, which are very cool. I like how the videos play on loops. The downside is you have to spend a lot of time trying to attract followers. In my case, I don't have that kind of time so my Tumblr site sits untended.