I don't usually go shoot at these events, unless I am being paid to do so. Honestly, I have better things to do other than trying to deal with the crowd and other inconsiderate photographers.
marcwang mentioned here, that "there isnt really much artistic value in those images". I agree totally, most of the time, sometimes if you are really lucky and get that one shot that is worth something or even putting it in a portfolio, but 9 out 10 times most of those shots aren't worth putting into a portfolio, but hey, the client wants them, so give them what you want.
Just my $0.02