Having your repeat students, when asked their reason for signing up for your class, say "because I really like [or in one case, totally love] the professor." (This was not said to me directly, but via some first-day, getting-to-know-each-other activities.) It's kinda awesome to have fan club. It's even more awesome when said fan club is made up almost entirely of very smart, very funny, and rather cheeky women.
Seeing this bumper-sticker on a student car on your first day of class: "The real Jesus forgives your Jesus for being a greedy Republican warmonger."
Finding out that the edition of the King James Bible that you'd ordered for your class on Big Johnny is actually a facsimile copy of the 1611 original. (All I'd wanted was an orginal-language edition, so I ordered the thing sight-unseen; I had no idea that it would turn out to be so fabulous or to have so many potential uses.)
Discovering that, although your freshman comp class this fall has weaker writing skills than the comp class you had last fall, it's 100% more lively and participatory--and you're thus unlikely to end every period in a murderous rage.
Signs that there's still room for improvement:
Deciding to wear, on the day that you intend to do a lot of chalkboard work, a black suit with a very flat weave.
Having a habit of making every author/character you paraphrase sound like a valley girl. ("So he's like, 'you're totally making a present for Baby Jesus, right?'")
Not bad, on the whole.