What do you like in a blog post? I know what I like and most of my "likes" have to do with formatting.
For me, the font must be readable. There's a reason most blog templates use old standbys like Arial, Courier, Georgia, Helvetica, Times New Roman, Trebuchet, or Verdana. These are all very readable fonts that are easy on the eyes. Some of the fancier blog templates use fancy fonts - you know, the ones that look like calligraphy or a kid's writing. These are very hard to read in paragraph form. If a blog has a hard-to-read fancy font, it won't make my blog list no matter how interesting it is.
Another thing I look for is justification. Is the blog text aligned to the left (which is normal)? If the blog writer centers his/her text, it makes it very hard to read as the eye has to find the beginning of each line. It also takes more time to read. So if the blog's text is centered, that blog won't make my blog reading list either.
Then there's the color of the blog. Recently, I came across a blog whose primary background color was black with a bright purple colored fancy font. ACK! I couldn't find the back button fast enough! Reading white on black is hard on the eyes.
And last, but not least, is music. Just because you like to listen to Metallica doesn't mean that I like it. As my internet connection is slower, sometimes the music doesn't start until I'm halfway down the blog post and it startles me. Being startled does not endear the blog writer to me so the blog won't make my blog list.