Neither. Hitler was loved, and Stalin was feared.
What I mean by that, is of course that it isn't black and white. Just because a leader manages to gain his peoples' affection and respect doesn't mean he's a good guy. And a leader making harsh choices for the greater good of his people, thus making them hate him, might have a point.
But, in a general sense, I'd just go with loved. Robert Mugabe and Colonel Gaddafi are two examples of leaders people hate, and with good reason. I don't really need to list any widely loved leaders to juxtapose against them, since the alternative pretty much has to be better.