For self defense, I'd recommend an art that 1) specializes in the clinch, and preferably one that also 2) addresses strikes. The myth about 90 % of fights ending up on the ground is total horseshit - what you do see, however, is that almost every fight involves clinching. Nobody ever stands toe to toe trading punches, unless both parties happen to be boxers or something. For this reason, I'd say Muay Thai is the first art anyone should learn if training for self defense. After that, probably judo (favorable over Greco due to the incorporation of trips, favorable over freestyle due to the upright posture, favorable over both due to the incorporation of jacket wrestling and submissions), then BJJ (superior on the ground, which is not a good plan A, but a great plan B if you still end up there).
Just my 2 NOK.