For those looking for something closer to the airport, Pho Duy II is probably the closest one (located about 1 mile south of I-70 on Peoria).

I'm disappointed in the lack of pho places in downtown Denver, but An's Lemongrass Grill serves some great pho. The portion is pretty small, especially price-wise compared to most of the others, but the broth was very flavorful.

In south Denver, Rolls & Bowls in Lone Tree is decent.