A completely overlooked staple is a navy blue oxford shirt. To be honest, they are pretty hard to find. Most darker shirts like this are either flannel or poplin; it’s very rare that you find actual oxford cloth. I saw this the other day, and immediately added it to the list:
Gitman Vintage has released their version, which may be perfect. Slim cut, oxford cloth, and white buttons. It’s available over at East Dane (in white as well). Here’s the thing with this shirt: it shouldn’t be dry cleaned. Get it, and wear the hell out of it. You think regular oxford blue wears in nicely, wait until you see how great the Navy blue looks after a few washes. Gitman Vintage runs a touch on the small side, so I’d size up and put it in the dryer for 10-15 minutes, then hang dry.