I like randomness, as long as it comes at the right times and in the right quantities. I originally adopted the username 'apenwarr' based on that idea.
Apparently I'm not the only one to think of it that way. See The Serendipity Curve. She has the interesting idea that in modern society, randomness is getting reduced down to dangerous levels, so that we have to actively try to add randomness back in.
That's probably why weblogs are so popular nowadays: the most popular ones mostly stay on a particular theme (ha, that rules me out) but they still have random digressions, unlike, say, the business section of a newspaper.