For me, the most desirable method changes based on the context. In the context of Alt+Tab between applications, I agree that MRU works best. (Even though I get annoyed when I get a third application in the loop and accidentally tab to the wrong one, it seems like the "habit" business would just make the order of switching unpredictable, which would be even more annoying.)

However, in applications like Firefox/Chrome, where the tabs are always visible, I'm the opposite from you: MRU behavior drives me absolutely bonkers. This is because the actual order of tab switching no longer matches the order implied by the visual position of the tabs. To my disgust, Visual Studio changed to this MRU behavior in (I think) 2005, and ever since then the Ctrl+Tab behavior has been useless to me, because even though the tab I want is right next to the active one, it might take six or seven switches to reach it. My memory of the order of the most recently used tabs while I'm coding is poor enough that the ordering might as well be random.

If you wanted to keep the MRU method in this type of application, I think a solution is to automatically reorder the tabs. But VS at least doesn't do this...not sure about Firefox (it didn't originally, and I turned off the feature ASAP).