BuzzBuzzHome's infographics have been a HUGE hit, and were some of our biggest hitters.
Here is an example: http://blog.buzzbuzzhome.com/2011/08/how-h-o-t-is-toronto-condo-market.html
People liked the information, ease of understanding, and it gave them better insight into the market.

We've been blogging now for around 3 years and do keep track of what gets traction and what doesn't -- here are some things we've noticed:
a) Monthly market reports (which is what makes up for 95% of most Realtor website blogs) get VERY LITTLE action. Especially the type of market reports that are straight from TREB's market watch numbers. "Interesting" market reports do much much better (like the infographic example)
b) Project specific - we do a lot of condominium projects, and depending on the "hot" project of the month, that particular project will get a lot of action. This month, Bond Condominiums, Yorkville Plaza and B.Streets have all been smoking hot (and we have VIP access to all 3! :) )
c) Rendering posts: People love to see images. Anytime a new development releases renderings, we devote an entire blog post to them.
d) Special Offers: Who doesn't love special offers? If ICE CONDOS are selling at 10% down and cheap parking, our readers what to know about it!
e) Market analysis of specific projects: Full market analysis of individual projects really set us apart in our early days (Example here for THE YORKVILLE - http://www.talkcondo.com/toronto/the-yorkville-residences) However, each analysis takes a minimum of 8-12 hours to prepare which is probably why we don't see a lot of Realtors do them but they are hugely relevant and beneficial to our readers.
Nowadays, developers don't like us releasing pricing information so early - so we only send these reports out to our newsletter database and then the website gets updated once the pricing information is public (sign up to our newsletter here: http://www.talkcondo.com/subscribe)
f) Voice - this isn't a "post type" but ultimately your readers are coming to you for your VOICE - who you are and what you say. Your posts should reflect this. BuzzBuzzHome are a perfect example of a site with a VOICE and PERSONALITY. Their readers know who they are and they are true to themselves. There are agents out there who have done an incredible job of finding their "voice" online. This above all else is the most important aspect - once you find your voice, it becomes very easy to figure out what people come to you for.
Hope that helps!

I find 99% of Realtor blogs are useless and are only used to show listings, sales & open houses. The only ones of use and those that offer more in depth information and show time and effort have been spent on them.
I'm actually shutting down my blog as I know I'm not doing it justice. It's not a priority to me, so it doesn't show the attention and effort I put into my business. I think many agents need to realize that you don't have to have a blog, twitter account, facebook etc.
They're all only useful if you're willing to commit the right amount of time and effort in them. Better to do a better job with less, than try and be on every social media trend out there.

^^Great points @Amar, and I totally agree that you should focus on what you are good at and expand upon it, rather than spreading yourself too thin.
However, when it comes to blogging, rather than just shutting it down, why not set aside a certain amount of time on certain dates to work on postings? For example, Mondays and Wednesday's from 6am to 7am, you are dedicated to the blog.
Further, you can make the blog work for you, rather than working on the blog. For example, your blog specializes on pre-construction in Vancouver. Why not just make it all about photos? I am sure that you go to hundreds of events a year such as launches, ground breakings, and sales-centre visits.... just snap some photos and post them! See what happens.
People love images!

@Roy - your findings don't really surprise me.
Stuff like market reports are so widely available that people will just get them from the source, rather than a realtor commenting on them (unless of course it's you guys at talkcondo, cos you're awesome!)
Images, project specific info, EXCLUSIVE insight - that's what's interesting.

Coming from a developer's perspective, we have found that the biggest draws by far on our blog are all related to our specific projects.
Articles such as construction updates, exclusive rendering releases, and releasing information about new sites always get the best readership - it just shows that these are the types of things that purchasers (and industry professionals) want to see when checking out blogs, and social media in general.
http://blog.mycondomylife.com/cityzen-developments/

Amar said:
I find 99% of Realtor blogs are useless and are only used to show listings, sales & open houses. The only ones of use and those that offer more in depth information and show time and effort have been spent on them.
I'm actually shutting down my blog as I know I'm not doing it justice. It's not a priority to me, so it doesn't show the attention and effort I put into my business. I think many agents need to realize that you don't have to have a blog, twitter account, facebook etc.
They're all only useful if you're willing to commit the right amount of time and effort in them. Better to do a better job with less, than try and be on every social media trend out there.

You're absolutely right Amar. You have to want to blog in order to provide content people will want to look at. Bottom line I don't think that most people really care about Realtors sales and open houses. I think it would be better to provide education about the home ownership process and give people information why it's in their best interest to use a Realtor.
Blogging about community events, local businesses in your target area and perhaps pre-sales in that area would also bring some good traffic to your blog.
I also liked Matthews idea of posting pictures. Pictures tell 1000 words and most Realtors don't take enough of them of their listings.
Google also likes fresh content and a blog is a great way to accomplish this. You are more likely to be indexed and your site will show higher in the rankings.