Pho favorites, Mtn.View & Sunnyvale
Pho Binh for a nice flavored clear broth that when salted correctly, I feel doesn't rely on MSG like other places. I used to like Pho Vi Hoa which is probably the best for MV/Los Altos, but they're pricey and come to think of it not always stellar and maybe a tad bit MSG heavy but I could tolerate it better than a bad Shanghainese restaurant.
There are no good pho places in Mountain View. In Sunnyvale, go to Pho Queen (Lawrence & Tasman). The owner can be a little bit of a soup nazi but it has the most authentic, non-watered down pho I've tasted for the area. My definition of good pho: clear yet flavorful broth, non-gummy noodle, tender meat, good ratio of broth to noodle/meat (2:1). In addition to the usual basil and sprouts, the accoutrement plate should include lime, not lemon.
I second KathyM's suggestion of Pho Queen. Initially, I had my doubts about the place, but once I tried their pho, it compared very well with my favorite joint Pho Bang (on Tully Road in San Jose).
Their pho extras like scallions, fatty broth, beef balls offer a nice option to mix and match if you're tired of having the same Pho Ga, Pho Bac Dac Biet, etc.