Our vicar turning the church notices into a second sermon: he does it every week, saying things like "It's church cleaning on Tuesday, we need the church to look spick and span after all the events this week, if you can spare an hour please come along, many hands make light work, blah blah blah...". Yes, those who actually do the church cleaning have been there far longer than he has. Sometimes he sounds like a comedian desperately improvising to fill a time slot, or a contestant on Just a Minute.
Christmas. Most of it, especially as it's the same every year.
Loads of other things already mentioned here, but recently, this dialogue, which I've had with several people:
Them: Happy new year!
Me: Happy new year.
Them: Did you have good Christmas?
Me: (thinking Scrooge-like thoughts) Yes, thank you. Did you?
Them: Yes, sorry it's over, back to reality...
Me: (delighted that it's over).
Grrr. So tedious, like Christmas itself.