I think I might disagree with a lot of the other posters, but here goes:
I like a professor who lectures for pretty much the whole class, and doesn't let themself get derailed by off-the-subject questions. It's Ok to tell a student who has asked an irrelevant or off the topic question to "see me after class" or "talk to your t.a." instead of making the entire class sit through pointless backtracking.
I don't like class discussion - I am paying for an expert to explain things, not to listen to a bunch of other students talk about all sorts of stuff - those discussions belong in a Teacher Assistant led session, in the student union, or on the internet, not in the main class.
I like a well organized and pertinent lecture - if a professor has run out of things to say, fine, dismiss the class, don't just repeat the same junk or talk about movies, tv, or current events (unless it really relates to the topic at hand).
this isn't to say that human warmth and empathy is not important, it is, but I personally would rather keep to the subject and hear what the professor has to say than let showboat students (there are always a few) take over.
I like a professor that relates some career advice in a class - if these students are training to be scientists, try to give them some practical advice about how to succeed in that field.
Humor is always good.
Also I have to agree with Sailor Saturn that it's important for an instructor to admit when a student is right about something, it's always sad when the prof pretends not to have heard you
A quick note on testing: multiple choice tests are almost impossible to make well - there are almost always ambiguities in language that lead to questionable answers. Same with true/false. Essay/performance/computation show-your-work tests are the only way to go. That and Interpretive Dance
May you walk on warrrrm sannd....