Given my natural aversion to *usted* in Spanish and *vous* in French, I'm starting to think that out of consistency I should adopt the Quaker *thou* in English.
Unfortunately it's a tough bind because the Quakers originally adopted it out of a democratizing instinct — *thou* was the familiar second person and *you* the formal — but in the modern era it sounds archaic, making it sound MORE formal than *you*.
Also it's a very weird thinking to do.
I also really prefer to use informal forms in Japanese, and that is an intermediate case between Spanish and English. In Japanese everyone grows up fluently using informal forms so it's not nearly as weird, but I get the impression that if you use informal forms with bank tellers and waiters people will think something is off (though I haven't spent enough time in Japan to know exactly how this plays out).
