^^^I'm in a similar boat - one waitlist, two rejections, a few pending.
Without know anything about your SOP or research background in the past I'd suggest it is likely worth retaking the GRE. I don't think a high GRE is enough to get accepted, but a low GRE is likely enough to get rejected. It's also one of the few things you can directly control.
Certain research agendas may be more favorably reviewed year to year depending on who is on the committee and all the idiosyncracies of selection. But a high GRE is something you have direct control over and is a very objective measure.
