I like to be front and center so I can take a lot of pictures, and that is most important. I will dance a little if the music calls for it, but I'm not going to anything crazy. I dislike it when people sing along because it seems to me that, no matter how loud the band is, I can still hear people in the crowd belting out lyrics that are a little off and notes that are not on pitch.
Also, I hate, hate, HATE when people in the crowd clap along with the song. I don't know why it bothers me so much, maybe it's just because the shows I go to attract the same crowd, and I always see the same little group of people trying to start some claps during every goddamn song. Honestly, if the band wants you to clap to their song they will start the claps themselves.
Related to that, there are these two girls I see at every show I go to in Fargo. No matter what show it is (all-ages or not), they always show up right before the headliner, drunk off their asses, push all the way up to the front, where I am at, and try to shove everyone out of the way so they can be front and center. And they do a lot of fist shaking. During every song. And sing along. They are the ones that start clapping all the time. Also they both have very large, curly, afro-like hairstyles that pretty much block your vision.