Where to start? Well, why don't I start with the end - specifically Phil Harland in Religions of the Ancient Mediterranean examining apocalyptic visions.
Staying with Near Eastern and non-western cultures, Frog in a Well has a post about seventh-century BC guidelines for Chinese students, with some comments about how they inform the attitude of current students (which, having spent a year teaching in China, I can vouch for). Meanwhile, Rich Baker gives a useful ten paragraph guide to Ancient Egypt.
I didn't know much about the mediaeval bloggers out there, so this was a revelation. In the Middle has an interesting post on man-eating animals in mediaeval art (and early Christian literature). Aliamore's Edward II blog is a tremendous resource for the ill-fated Plantagenet - I can't single out one post, as they're all excellent. And, straying out of period, Another Damned Medievalist talks about the role C.S. Lewis and J.R.R. Tolkien may have played in forming modern views of Islamic peoples.
There's been some debate about the state of Anglo-Saxon studies. It was kicked off by Michael Drout here. A number of the responses are to be seen here, but there have no doubt been others.
I read the ancient blogs after the mediaeval ones, and I was probably a bit tired by then. So the ancients may be a bit neglected. Nevertheless, I did find a new blog I wasn't aware of. Classics Reloaded is the product of an undergraduate Classics Studies major, who shows more intelligence and perception than many graduate students I've come across. They must be a delight to teach. The best post is their discussion of the Melian dialogue in Thucydides. I was recently writing about the Dialogue in another context, and I agree with MJD that Thucydides intends his readers to believe that the Melians are right, both morally and in terms of Athenian self-interest (though part of his message is also that being right doesn't necessarily save you). Their post on Sophocles' Antigone gives me a way to mention the much-blogged (e.g here) book report on the play by a young Britney Spears. She seems to have read the work and understood the plot, which was probably all that was expected of her.
Alun Salt always gives good value. In i-Science, he has a sensible discussion of The Star of Bethlehem, including one of his genius remarks towards the end. Meanwhile, in Archaeoastronomy, he reflects on the second season of HBO's Rome series, just begun in the US, and mentions Mediawatch-UK's qualms. For those of you who don't know, Mediawatch-UK are carrying on the work of Mrs Mary Whitehouse, trying to stop British broadcasters exposing those incapable of turning their televisions off to the merest suggestion of sex. I saw one of their spokesmen recently on a programme about Monty Python's Life of Brian, talking about how Christians were at a disadvantage when dealing with their opponents, because Jesus told his followers to turn the other cheek - in a tone of voice that suggested that he really, really wished Jesus had been a bit more hard-nosed about this.
In the more professional end of the blogosphere, I've been meaning to mention Mary Beard's A Don's Life for some time. Beard generates a wide range of reactions. My own view is that, while sometimes she paints a picture of university life that bears little relation to any experience I've had, on other occasions she can cut right to the heart of the issue. A couple of recent posts caught my eye. In one, she compares exam papers from 1902 and 2006, and discovers that the Edwardian papers required more knowledge, but less actual thinking. In another, she discusses ancient racism, in response to a recent controversy on British television. Personally, I find it difficult to read Juvenal's Third Satire and not conclude that Romans could easily hold horrible prejudices based upon someone's ethnic origins - whether you call that racism or xenophobia may be hair-splitting.
A couple of posts dealing with the move from late antiquity into the early mediaeval period. Muhlberger's Early History spends Christmas Eve blogging a couple of articles, one of which reminds us that Egypt was once a centre of Christianity (this connected for me with the first episode of new BBC4 series Art of Eternity). Meanwhile, Carla Nayland discusses what seems to be one of the more sensible books on King Arthur. I'm glad to see that I'm not the only one to recognize that Gildas doesn't actually say who commanded at Badon, and certainly not that it was Ambrosius Aurelianus (who personally I believe was dead long before).
A few more Roman links: At Westminster Wisdom, the Gracchi have an in-depth (if occasionally poorly-punctuated) discussion of Fergus Millar's The Roman Republic in Political Thought. Meanwhile, David Parsons on the ARLT blog has a sensible post on teaching Latin. His conclusion: that promoting the language is more important than internecine arguments about which course one uses. And I include Troels Myrup's post on a talk at the Getty Villa purely for the photo of the villa itself, which immediately made me think of villas in the Sabine Hills, such as Hadrian's at Tivoli. (The Getty Museum has, of course, been in the news a lot recently with regard to demands for the return of allegedly-looted antiquities. rogueclassicism carries all the latest news reports.)
Finally, some fun ones. Adrian Murdoch at Bread and Circuses gives some rules for writing about late antiquity. Susan Higginbotham presents a playlet which in one short paragraph expresses all my qualms about Richard III's apologists. And whilst this post has nothing directly related to pre-modern history, Richard Nokes is a professor of mediaeval literature, and the little playlets at the end are hilarious.