BLOG: Welcome to Optimism 
WHO WRITES IT: Creatives in the London office of ad agency Wieden+Kennedy
WHY YOU SHOULD READ IT: Because any blog with "optimism" in its title and the tagline "embracing failure since 1998" is worth reading. Wieden+Kennedy's photo-filled blog gives outside ad rats a shot of the agency's quirky, free-wheeling, and yes, booze-filled culture. We love the pic of Blender Man, the agency's lobby-based mannequin that reminds people to "walk in stupid every morning," Brit-speak for keeping an open mind.
BLOG: Inside BzzAgent-BeeLog 
WHO WRITES IT: Employees at the word-of-mouth marketing shop
WHY YOU SHOULD READ IT: Because this is an honest blog. Posts include acknowledgments that they're not always good at handling the press and notes about how they're revising their mission statement. Read about the next board meeting, including part of the "Planning to Exit" slide, which not-so-subtly mentions mergers, direct sale, and valuation. Hello, I-bankers!
BLOG: Google Blog 
WHO WRITES IT: Employees
WHY YOU SHOULD READ IT: Because who doesn't want to know what it's like to work at a company that's hiring as many people as Google? Yes, it's more than a little ironic that a company that reputedly fired an employee blogger could have a pretty good cultural blog, but in between the posts hyping Google's new features, there are bursts of authenticity. One data-center technician describes a mural he painted in an otherwise bland area of the Googleplex, while another posts a missing-persons ad for a search-engine optimizer who hadn't been seen for a week. They found him. Whew!
Read more about brand blogs -- and nominate your favorite blogs of any sort -- at www.fastcompany.com/keyword/bestblogs .