Obviously whoever came up with this "feature" didn't do much web development.   As you define which CSS class should be applied to an element by setting its ID tag, you'll find that as soon as you paste something in, all your ID tags become tag1, tag2 etc.  For a table cell, for example, you get ID="TD1", ID="TD2".

Now, I can uncheck the box easily enough, but whenever I create a new project, there it is.  If you know of a way, to turn this thing off once and for all, for every one of my Visual Studio projects, now and forever, I pray thee step forward as this thing is the bane of my existence.  Microsoft, of course, contributes nothing new.   

While I'm at it, finding this option wasn't so intuitive either.  What makes it qualify for the Miscellaneous node and not the general node?  And wouldn't "Format HTML on paste" right below that, belong under the "Format" node? 

Hulk Angry!  Hulk Smash!