Hahn BMW, Yakima WA
I had a very good experience here purchasing my 128i. I also bought my previous car, a 318ti, from them and had it serviced there from time to time.
Hahn treats buyers of new BMWs quite well, including, in my case, buyers of the "low-end" models. Pricing and trade-in allowances are not extremely generous but are probably better than any others in the Northwest. I got about a 2.7% discount off MSRP, the best I could get elsewhere (Bellevue) was 1% on any 1-series. At Hahn, you can get to their best price with minimal haggling, basically just by asking them. Tiho Krtalic, who handles BMW sales there, is very knowledgeable and professional.
Their service and parts departments seem very competent and courteous. Service will arrange loaners when they have your BMW (if you bought it there, not sure otherwise) and the loaners are usually nice cars, typically a 3-series or X3. This is a big help if you live out of town, as I do.
Hahn is a fairly small dealership and their in-stock selection can be limited, for example they seldom have any MT cars to demo, just automatics, also often only 1-2 1ers on the lot. I factory-ordered my car and am very happy with it, but might have done a couple of things slightly differently if I had been able to compare more cars. So do your homework first if you want to buy through Hahn. Otherwise, they are excellent.