Common Goldeneye

Classic common goldeneye, no reason to think it's a hybrid with a bufflehead just because it's hanging out with one. They do share the same habitat, they are likely to bump into each other every now and then :)

http://www.sibleyguides.com/2010/01/distinguishing-female-barrows-and-common-goldeneyes/

As mentioned before by Malcom the Sibley's guide bottom drawing shows on variation of a sloping bill from forehead. The difference still is the top of the head. Common crests back and Barrow's is forward. Like the difference between the Scaups.

Don't see the Bufflehead. But if you want confirmation on what it is I would suggest posting on the Bird Forum http://www.birdforum.net/forumdisplay.php?f=114

I don't see any suggestion of a Barrow's though

I was looking at the wings and the contrasting white patch indicates Common rather than Barrow's. Going by my book the bill size looks too big for either but they are only drawings!

You never know. Someone spotted a Common X Barrow's male.

https://www.allaboutbirds.org/guide/Barrows_Goldeneye/id I forgot to mention that the head shape is wrong for Barrow's

No it's a common. Barrow's have almost complete yellow bill as the female Common is mostly dark with yellow near the end.