Best? They should all be almost exactly the same. Almost all are at community colleges or universities. Pick the one closest to you. Did Kaplan actually tell you it matters? Their focus on the irrelevant boarders on incompetence. There are no tricks or quick fixes. I have heard about bad test centers people have gotten stuck with, but it was the proctors (and they are not constant) and rarely happens.
Do you work for Kaplan? Has anyone taken the LSAT on a flip top desk? Ever? I have never seen a test center (regardless of whether I was taking it or not) that used flip top desks. All had desk tops- All.Focusing on something like this is a waste of time and effort and will drive you crazy. Focus on the questions man, not whether the test center has florescent light or not. Do not worry about the test center- you have enough to worry about- frickin Kaplan.