My least favorite in order:
1. The Circuit Overseer's Visit
2. The Special Talk
3. The District Convention
4. The 2 Day Circuit Assembly (remember when it started Friday night and ended Sunday night?)
The Memorial was ok if it landed on a meeting night. Generally the memorial was 45 minutes versus at least an hour for the other meetings. However, you always had those over zealous congregations that rescheduled the regular meetings.
Speaking of boring memorials, do you remember about 15 - 20 years ago they gave the memorial talk and after it ended someone else got up and talked for another 20 minutes. I am still mad about that.