Hard to say.
Hated the Theocratic Ministry School when I had to give a talk. Absolutely dreaded it. When that time came, no meeting could have been worse. When I wasn't on it, it wasn't bad.
The Service meeting was sometimes enjoyable. At least some of the sketches broke the monotony. Some people would even try to be funny. And there were always the local needs parts where you kind of got an "in" to the gossip and got some feeling to what was going on.
Otherwise, Sunday meetings were the worse. And that was the Public Talk and Watchtower study. It was a weekend. Sitting around in a suit, going through that boring question/answer format was one of the worst things to endure on a weekend when you could have been doing anything else.
Public talks weren't so bad. At least it was about an hour with one person talking and a semi-consistant theme.
I guess no matter what meeting it was, I was usually daydreaming or trying to sneak something else to do (read a book, etc.). So in that sense, the questions meetings were worse because there was pressure from my parents to make a comment so I couldn't totally zone-out.
-j.w.s.