I get sick of hearing the first 10 seconds of Hell's Bells, Paranoid, Enter Sandman, etc, between plays! Its just dumb. Before the game and halftime, maybe after a score, are the only times I think it is appropriate.
It would be nice to understand the PA anouncer. Actually it is a safety issue as well - in case emergency instructions are needed. So, I guess I wish they would shutup more, but have a better sound quality for when the audio system is used/needed.