For Google, I often find myself smuggling a "hl=en" into the query parameters. This works on almost all Google services, and is quicker than finding out where the language switcher is hidden in the UI.
I wrote a small greasemonkey script to add hl=en to all except a select few google locations. They are the most egregious. Unfortunately for us the industry has chosen to go with IP address determines language and it's getting more and more common.
I DO have accept language configured in my browser and I also DO understand that statistically many people's browsers are mis-configured. NO. I'm not leaving my browsers logged in to every site in the internet.
We'll forever be tilting at windmills.
Another common problem.
http://searchengineland.com/google-ncr-no-country-redirectio...
Despite the positive worded arricle, apparently Google hasn't brougt /ncr back yet.