Alright Neile, here is my humble opinion. There are different definitions of a great blog. Maybe it's a blog that gets a lot of comments or a lot of people reading it because it provides great information or maybe it's a blog that does a lot of reviews/giveaways; however, for me great blogs are the ones I enjoy reading: the "real blogs" of people I can relate to. The blogs that aren't over-done with fancy headings or sidebars - the blogs that I can connect with. As a mom, I enjoy reading other "mom blogs." I appreciate the support and connection I get from the blog connections I make. It really is an amazing community - something I have come to value immensely.
A blog or blogs that keep me informed in subject matters I am interested in with a personal touch to who they are and what is going on in their lives.
I like a blog that I can relate to as far as the stage of life I am in (wife and kids), my interests (local food, farmers markets, cooking), and one that is well-written with good pictures. It does not have to be flashy, just real - authentic women sharing their lives.The Park Wife
Being a blog author and reader for 2 years I have read my fair share. I enjoy blogs that talk day to day life, fun and upbeat but doesn't sugar coat the bad days. Basically a REAL person. I have always tried to be me with all my faults and that has always done me well on my blog :)
I like fresh, positive content (not so much the "I'm know I haven't been updating but I've been really busy" posts every four days!) and an authentic voice!
For me, first and foremost, a blog has to be well written. I like blogs that I can relate to, but that also offer a perspective that differs from my own. I like a mix of personal and informative posts. As a blogger, I like to read posts that inspire me to write posts for my own blog.
I second all the comments above, especially about being well-written. Good writing can get me interested in topics that don't necessarily relate to my own life. But I would add one new criteria on a good blog: interactivity. I can't say I've quite figured out how to create/channel that, but it's good when it happens. Comments (and responses by the author), contests, collaborative items, q & a pieces, etc. ... anything that gets the reader involved and creates interaction with the writer. So, basically, this post is a great example! ;)
I can be entertained by the simplest topic if the writing style is intriguing and engaging. I like real, but I can't define that term. I just know it when I read it. If I click away feeling like I just had a conversation with someone, or I just learned something, then that makes my day. If I giggle, or cry, or THINK, then I will definitely come back for more. Writers who are all of the above rock my blog reader.
The writer must have an authentic voice and subjects must be varied, stimulating, and well-written. Save the 'what I had for lunch' type info for FB or tweets. Informative and interesting subject matter with universal appeal is what prompts followers to weigh in...