I love SHIELD. It's one of my favorite Kirby creations, and I'm especially fond of its original incarnation from Strange Tales, when it was still a The Man from U.N.C.L.E. knockoff.
Every now and then, however, I find myself thinking that such a far reaching, powerful, resourced instrument of The Man, with all kinds of lethal toys at its disposal, and agents everywhere, would not likely have tolerated the kind of chaos that walks one step behind most superheroes and supervillains. So, if we took SHIELD to its logical extreme, what Marvel characters from Marvel's 1961 birth through today would SHIELD have decided needed removing?
The first, perhaps most obvious in my mind, is The Hulk. Too powerful, and too unpredictable.
Another is Dr. Doom. I don't think it would have taken more than two ventures outside his own borders for SHIELD to decide this guy needed to go.
Your candidates?