Saturday is (in my opinion) the craziest and most eventful day of the tournament. This year, my group arrived by a chartered bus at 8am -- which apparently was still not early enough to get into 16th hole. If you're brave enough to stand in that line for 3+ hours to get in, I commend you but remember there are plenty of places to post up for the day. Tilted Kilt has a great patio that looks the fairway of the 18th and they don't pack people in there so you don't feel like a sardine. The only downside of Tilted Kilt is if you're looking to watch golf, this might not be the spot for you -- you can't really see them tee off or the green.
Going to the open takes a lot of preparation (especially on Saturday) so save yourself the headache by getting there early. If you're not into crowds or long lines, Fridays are a much better option for you. Enjoy your time at "The Biggest Party on Grass".