As close as possible to the front for speedier departure once you get to Vegas! As Trey said, A1-A15 are for Business fare/A List and a lot of the flights I've been on there are hardly 3-5 people in that group. A35 will get you a nice window seat close to the front. You know how they say the people in first class get to glare up at the poor people in coach as they board behind their newspaper? Yeah on Southwest that's what it feels like to board in the A group..Hehe