Actually, the FA's in olive oil are primarily monounsaturated, so they're really omega 9 (oleic acid). Both omega 6 (linoleic acid, arachidonic acid) and omega 3 (linolenic acid, EPA, & DHA) FA's are polyunsaturated. Only omega 6's and omega 3's are essential, so don't think of olive oil as an EFA source. However, it is still a "good fat," because monounsaturated fats have a couple of uniquely positive aspects: (1) they have antioxidant capabilities in the body, and (2) their intake is correlated with increased testosterone levels.
As for the real EFA's, don't even bother trying to add any omega 6's to your diet. You're probably getting more than enough already, as long as you're eating as much meat as you should be. Corn oil is one of the richest omega 6 sources around, and corn is what fattens up American cattle, chickens, and pigs. Of course, corn in its natural state contains very little fat of any kind, but the concentration of omega 6's goes up as you ascend the food chain (kind of like with mercury and fish - the bigger the fish, the higher the mercury level).
Omega 3's, as you're probably well aware, are notoriously underconsumed in the SAD (standard American diet). To correct the omega 3/omega 6 ratio in your body, you'll need to resort to a concentrated source of omega 3's. You have basically two options, fish and flax. Whether one is better than the other continues to be debated, but I recommend both.