Below I've also compiled a list of some of my favorite blogs by category, and a short description. This seemed like a pretty simple idea at first but then I realized how many different things I read. Perhaps an ongoing project?
American Politics
+ Show Spoiler +
In the interest of full disclosure, my politics lean left (using the American definition). I used to follow several more blogs, but I eventually removed the ones with heavy posting frequency (ex: DailyKos, Americablog) because there was just too much to go through, and ultimately I felt that half of the stuff really wasn't *that* worth reading at the moment. That is to say, I would have been perfectly fine reading a more organized, analyzed, and consolidated version later on. Different blogs have different purposes, and compile information accordingly.
538
Probably one of the better known blogs on political polling and statistics, Nate Silver does a good job of taking a whole lot of numbers and explaining what they mean. For example, if you're curious why Obama's projected advantage in the presidential election is arguably a bit larger than it actually seems based purely on popular vote projections, this is the place to go.
Obsidian Wings
Because it's a group blog, you get a nice mix of posting styles. Some of the authors look at things from a statistical perspective, others philosophical, still others sociological. Covers a fairly wide variety of topics, generally somewhat related to politics and/or society. Not always light reading, but in general it's clear that a fair amount of thought is put into posts.
The Republic of T
Probably one of the more outspoken left-leaning blogs I follow. I like his writing style not due to any political preference, but rather because pretty much every single one of his posts (excepting the ones in which he links to other blogs talking about a given topic each week) are extensively sourced, and make more great reading if you're interested in learning more about a given subject.
Anime/Comics/Manga/Games
+ Show Spoiler +
Awkward Zombie
Video game webcomic by Katie Tiedrich about a wide variety of games, and (in my opinion) consistently amusing. In particular, I enjoy Smash Brother comics, though the ones she does on WoW and Fire Emblem tend to be very good as well.
Escher Girls
A blog that perfectly illustrates how female characters in fiction (primarily American comic books, but not exclusively) are drawn in impossible or ridiculous poses or with disturbing anatomy because the artists feel a need to show "teh sexy". As an aspiring manga illustrator, I really like this blog because it also posts redraws or drawings with poor anatomy, showing what the characters might look like with more believable anatomy, and generally improving the sense of believability in your drawings.
Frazz
In my mind, the American comic strip that comes closest to the magic of Calvin and Hobbes. Not quite there, in part because Bill Watterson was simply a genius ahead of his time, but one of my favorite ongoing comic strips.
Pearls Before Swine
Another great comic strip that doesn't take itself too seriously, a fresh breath of air from the... let's just say "consistency" of Cathy, Garfield, and the Family Circus. Don't get me wrong, there's a time and place for Garfield, and I'll certainly admit to chuckling at a few strips here and there. The incongruity between cute anthropomorphic characters and the dark themes surrounding them is also quite funny.
The Oatmeal
I'm fairly certain most people here are familiar with the Oatmeal already. Go read it.
XKCD
Also a blog that I'm sure 80% (conservatively speaking) of TL reads. Still, putting it here because I can't risk someone missing it.
Exploring Believability
As someone who dabbled in game and manga design before, this is arguably one of the most fascinating blogs I subscribe to. J. Shea's stated goal is to "talk about fun", but the blog is about so much more than that. Discusses the role of clothing, atmosphere, consistency, color, psychology, and other themes on the subject of video games.
Sociology
+ Show Spoiler +
Alas! A blog
I hesitate to categorize this under sociology because it covers a wide variety of topics. The blog itself is somewhat similar to the likes of Obsidian Wings mentioned above in terms of topics covered (though it does have a bit more posts regarding feminist and LGBT issues), but I like it because of the culture the blog comment section has developed, making it one of my favorite places for mature back and forth discussion between mutually respectful viewpoints. In this day and age of the internet, that's pretty rare. TL does a nice job through moderation, but sheer volume makes it hard to really discuss anything because there are just too many people involved in any given conversation. That's one of the pros of having a relatively unpopular blog, haha.
Pigtail Pals
Don't let the name turn you off, this is a *very* interesting blog, mostly because it talks about stuff I actually have very little personal experience about - raising children in the (American) consumer environment. It helps explore and challenge societal conventions, and I think that's a wonderful thing, in that it helps me to think about things from a perspective I might not have considered before. Any blog that encourages parents not to pigeonhole their children into pre-defined gender/societal roles is a plus for me. I love it when girls love sports and play with legos, and when boys aren't afraid to learn how to bake and cook. Discusses childhood and what the writers perceive is the garbage being marketed to children, which is a pretty fair assessment.
Sociological Images
A blog by two sociology professors.The initial motivation for the blog was to create a place for professors to swap images, the goal being to encourage people to exercise and develop their sociological imagination by presenting brief sociological discussions of compelling and timely imagery that spans the breadth of sociological inquiry. Talks about advertisements, pictures, graphs, and photos with commentary.
Military
+ Show Spoiler +
Army of Dude
One of my favorite "grunt" blogs by an American soldier on the ground.I studied Political Science in college, and generally analyzed the military as a whole and conflict from a "macro" perspective, and it's great reading a blog that's not as abstract and constrained by convention. In a sense, somewhat similar to the great "Generation Kill" by Evan Wright, if it just followed the life of one soldier. The blog isn't really updated anymore because the author is now in school after completing active duty, but his archives are wonderful reading, and an important point of view to keep in mind as America is becoming increasingly divorced from the realities of modern war. To be sure, it's not a comprehensive view, nor is it always fair, but it shouldn't be.
IMINT
Open source military analysis, strategic thinking, and imagery interpretation. As a military nerd, this is absolutely perfect. In particular, I recommend this post on Taiwan's SAM (Surface to Air Missile) network. Once you get the hang of identifying things from satellite photos, wasting time on Google Earth because even more fun than it already was before. Wait... is that a decommissioned bomber fleet sitting in the middle of the desert?
Kings of War
Kings of War is a blog by various faculty and research students of the Department of War Studies, King's College London. Some of the stuff may be a bit overly abstract and philosophical at times, but it's pretty deep is you can keep up. The comment section is also very good when it gets started. That is to say, most posts don't receive all that many comments, but those that would be inclined to post here generally have something insightful to say.
MilPub
Group blog on primarily military issues. Great comment section, and the perspectives provided from several writers that used to be in uniform are pretty cool.
On Violence
A blog on counter-insurgency warfare, military and foreign affairs, art, and violence, written by two brothers--one a soldier and the other a pacifist. The blog primarily talks about foreign affairs and military culture. They explore the concept of violence using non-fiction, journalism, statistics, and history.
Random
+ Show Spoiler +
The Simple Dollar
"The Simple Dollar is a blog for those of us who need both cents and sense: people fighting debt and bad spending habits while building a financially secure future and still affording a latte or two. Our busy lives are crazy enough without having to compare five hundred mutual funds – we just want simple ways to manage our finances and save a little money."
The author of the blog (Trent) went through a complete financial meltdown, and threw himself head first into trying to figure out every nuance of fixing his financial situation, and after a few months began to get the picture. Within eight months, he had paid off all of his credit card debt, paid off his vehicle, and also established an emergency fund. Since he already had a passion for writing and had learned so much about how personal finance really works, he began blogging about what he'd learned to help people who were struggling with the same things. A must-read blog, especially for those of us in our twenties and early-thirties with a shaky grasp on finances.
Waiter Rant
As someone who used to work in the service industry, this blog resonates a lot with me. I think the most valuable thing Waiter Rant did for me was to create more empathy for others, and to think about the stories behind the lives of the many people you meet each day. It helps that The Waiter is an absolutely wonderful writer, and quite deep due to extensive life experience. Topics of choice run the gamut from rude customers to bad tippers to conversations had throughout the day. There are also often posts about things occurring outside the restaurant which lead him to observations and reflections. There are many references to his past as a seminarian, as well as posts referencing his work in mental health care at an undisclosed psychiatric hospital.
Informed Comment
Professor Juan Cole's (one of my profs at the University of Michigan) personal blog on the Middle East, history, and religion. Agree or disagree on his views, but he definitely provides an informed perspective no matter what side he takes on any issue.