What stands out in an admissions essay?

I have been working on my essays for some time now, I think they are solid stuff, but I always wondered if there was a common theme among great essays. For all you adcoms, what tends to grab your eye and draw you in? Should I throw in a quote relevant to the topic? Should I focus more on experiences or emotions? And what do you notice about poorly written essays? And do adcoms correlate essay writing ability with anything? Thanks.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums