In the "Big 3" of auto parts retailers (Advance, AutoZone and Oreillys), I've found OReillys to have the best overall service and parts needed are either in stock or available within 24 hours.
As far as oil prices, all retailers are overpriced IMO, but OReillys had some great deals last couple of years with reliable mail in rebates. For example, I'm sitting on 6 qts of PP and 12 qts of QS synth that I got basically free from OReillys after rebate. Plus, they usually have in-store manager specials on oil products, gotta check individual stores for details.
Speaking of details, OReillys has one of the better car care/detailing product selections, including 100% cotton chenille wash mitts from Viking, who is one of the top car care product suppliers in the biz short of buying the really good stuff online.
I have a brand new AutoZone within walking distance of my house. The Advance is about 2 miles away and is one of the nicest, most organized stores I've been in recently. I'd trade both for a well run O'Reillys.