The variety or cultivar selected will certainly have an effect on the overall flavor and characteristics of the oil. The characteristics and relative merits of individual cultivars are hotly contested. Most table fruit is unsuitable for oil production for a combination of reasons having to do with yield, size, and oil content. There are always exceptions. It is interesting to note that many of the attributes ascribed to single varieties disappear when planted in other regions with different soil conditions and microclimates. All in all, this is a fantastically complicated subject happily and inextricably woven into the unique fabric of the area where the variety is grown. The attitude that one cultivar or variety is superior to the rest is not only absurd, but positively dull. Variety in olive oil is indeed the spice of life.

The following list of cultivars accounts for the major percentage of all olive oil produced in the world today, but represents only a fraction of the known cultivars. Each has its unique characteristics, but some differences are remarkably subtle. Some are more durable, while others hold up better to heat. Some are rich, soft and buttery while others are big, angular and complex. The choices are delightfully limitless. Most are not sold as stand alone varieties, except in the regions where they are produced or at gourmet stores, where they are so ridiculously overpriced that it is an embarrassment to purchase one. The vast majority end up being part of some generic olive oil blend marketed under any one of dozens of different brands or labels around the world.
There is no substitute for personal experience. Try as many olive oils as you can. You will be surprised and rewarded by the rich variety and quality available at virtually the same price as branded generic olive oil when you purchase in bulk from single cultivar stocks.