There are a zillion brands out there so I go for whatever light-colored olive oil nonna at my local Italian deli recommends. This is for sautes and baking, so I don't want to add a lot of olive flavor. For finishing and dips, or dishes that would benefit from a stronger olive flavor, I'd go for something like the Greek oil you described.

I usually keep two olive oils around- expensive and a gallon container of olive pomace oil. The stuff is cheap and still imparts a mild olive oil taste.

I use the extra virgin olive oil from Costco. It's high quality for an everyday oil but not so expensive that I feel like I have to ration it.

I recently purchased Olio Santo, as I heard so many raving reviews for it. But I'm also thinking of using ITSJMAY's advice and getting a cheaper version as well. I really don't want to use the good stuff for everyday use.

California Olive Ranch.

As long as you go with a light oil, you should be fine. This article from the New York Times is an excellent "oil primer."
http://www.nytimes.com/2010/11/17/dining/17curious.html?pagewanted=all&_moc.semityn.www

I like Pacific Sun extra virgin olive oil from California: http://store.pacificsunoliveoil.com/?click=1019 It's a proven fact that many olive oils cannot be trusted for quality, no matter what the label says. Pacific Sun has won several awards and a bottle only costs $12-$14. I actually buy the 1-gallon jug for $50.

For everyday cooking but not to make vinaigrette for salads, Italian (but not Greek, please) olive oil such as "De Cecco" - about $15.00 a litter - and others in that same category are good enough. For salads, well, it is a total different story because one has to pay much more, however, it is worth. You may also look at the Spanish and Portuguese olive oils.

I like the big bottle from Cost Plus World Market! It lasts about 6 months in our house, and isn't super spendy, but still seems to be good quality.

I have a fabulous grassy olive oil that I use exclusively for dipping bread in (George's... it's affiliated with Zoe's Meats in San Fransisco and Seattle and other places), but for cooking I use Trader Joe's extra virgin or Costco extra virgin... both are just fine for that purpose (and for making salad dressings)

I have several finishing olive oils, but for every day I use my local store's extra virgin or trader joe's extra virgin. I would never use anything less than extra virgin though, it's not nearly as tasty and it's worth it to cook with good oil. Using good ingredients always makes a difference.

I also use the EVOO from Costco, one of only a few supermarket EVOOs that are truly extra virgin according to a study from UC Davis, skip to page 8: http://olivecenter.ucdavis.edu/news-events/news/files/olive%20oil%20final%20071410%20.pdf

I second LIEFIE on this - I always go for TJ's olive oil - they have several varieties, and the kind I get (President's Reserve, I think?) is a great value for under $6 a liter. Can't beat that! I also hear that Whole Foods in house brand oil is pretty good for everyday use, and inexpensive to boot.

San Giuliano extra-virgin olive oil from Sardegna! It's delicious!!!!!

For finishing oil and vinaigrette, I use Stonehouse California Olive Oil. I usually buy several flavors and they're wonderful.

For everyday cooking, I just use Costco's Virgin Olive Oil. For frying and sauteing, I really don't feel like I need extra virgin.

I'm another Costco EVOOer

Cullen Creek from Costco

I use Aldi brand Olive Oil, like $2.50 a bottle.

Nthing the Costco option if it's available to you. I try to get friends to grab me a 2liter whenever possible.

If not, Botticelli Extra Virgin is my staple and comes in at about $20 for a 3liter in Woodmans http://www.botticelli-foods.com/ It's good enough to dress a salad but not overwhelming or "too forward" Only downside is Woodmans runs out of it ALL the time.

I'm a fan of the california olive ranch everyday oil. Good luck finding your favorite!

I use Whole Foods house brand -- Whichever of their extra virgin house brand types is the cheapest, really. It's reasonably priced (even in comparison to regular stores- shocker!), delicious, and easy to find.

I use a bottle I brought back from Spain this summer for finishing. I'll be sad to run out.

I am completely hooked on Botticelli's Fruttato Premium Estate Grown Olive oil. It is totally Italian (just like me), first-cold pressed extra virgin olive oil with the most beautiful deep green color, fruity olive aroma, and deep olive taste. Which suits me just fine. The more olive-y, the better! It is about $19.00 a bottle. I use it for cooking, as well as finishing. I have no place in my kitchen for "light" olive oil.

If you are really looking for affordable, you can go for Goya.

Costco EVOO, or Costco Organic EVOO, or the big green bottle from World Market.

Please dont say EVOO again.

I have a friend who is an olive oil producer in northern California and he actually does not ever recommend cooking with olive oil. He says it should only be used for things that are cold or simply warm up. For cooking - roasting, sauteeing, etc. - you should use an oil that has a higher smoke point, like grapeseed or canola/rapeseed oils.