As I am big fan of being at the very front next to the stage, I've managed to get there for such crazy sold out shows as the Darkness and Velvet Revolver...without pushing and shoving, I simply got there first. I typically arrive to get in line a good hour and a half before doors open. Even if you are 30-40 people back in line just make a beeline for the stage when you get in and stake out a spot and you should be in a prime position to enjoy the show. Surprisingly a lot of people that stand in line really early tend to go to the bar or just mill around for a while.
I find that the front is better for a number of reasons, your face is out in the open, not directly behind a large, smelly, sweating somebody. You have the barrier/stage to lean on, so you give your feet a break, and of course you can see every member of the band, all the time.