Spanish is the way to go
I am a proud Italian, and if my relatives ever got word I was saying this, I would be excommunicated. The best olive oils are the ones from Spain. Greek olive oils are thin on flavor, and Italian oils tend to go towards the grassy taste with a peppery finish. But Spanish oils have big, robust olive flavors.
I was in the town of Olivas (how appropriate) in Spain and bought a bottle of oil that was there local "generic" kind. No, I don't recall the name, and I doubt you could get it here anyway. It was about the single best bottle of oil I have ever had. I have looked for oils from this area of Spain ever since, but with little luck...
Laudemio - from Tuscany - is a very peppery olive oil, but is about the best example of an Italian oil as can be found.
McEvoy is very nice for a Californian oil. They are growing by leaps and bounds, and not at all undeservedly.
As a gift, I was recently given a bottle of Australian Olive Oil - from a company called "Kangaroo Paw" (as in the flower). It has a nice, smooth finish with a hint of pepperyness. I just wish the olive flavor was a little bolder - but it is quite nice.
And I have also tried Giulianno Hazan's line of oils and vinegars - A&H brand. The olive oil was thin and totall uninteresting, but the red wine vinegar they make is the single best I have ever had.
Hope this all helps!