Top Tier Brands
The recommendation for fuels (with the exception of the new addition of the BP recommendation) has been the same since the X3 was introduced in 2004. And even though I have not read the manuals on other models, I would assume the fuel brand recommendation runs across the entire BMW line-up.
I have followed the recommendation for using Top Tier brands (better detergent, less build-up in the engine) on my 2005 pretty faithfully. Zero issues with the vehicle for 125,000 miles. There is a Conoco station on my way home that is within a few pennies per gallon of the cheapest retailer, so I usually fill up there.
In Colorado the Top Tier retailers are Conoco, Phillips 66 and Shell.
I also run a bottle of Technron through the engine every 5000 miles or so. Other cleaners are pretty good, I think, but Techron (same additive as in Chevron fuels) is readily available in retailers here.
Our BMW: '14 X3 35i, Deep Sea Blue, Black Nevada Leather, Fineline Wave Wood, Satin Aluminum Roof Rails, Premium Pkg, Cold Weather Pkg, Navigation System, Driver Assistance Pkg with ALL them cameras, Premium Sound
Our truck: '03 Ford F350, 7.3L turbo-diesel, 4WD, Lariat package, Lear topper, cow catcher, Blue over Grey (Go Rice!)
"Old Faithful's just a fountain compared to the glory of true love" -- John Prine