I like hard games. As long as there's a way to beat the enemy without resorting to exploiting or excessive grinding, bring it on.
I dislike games where you can adjust the slider on the fly (like Diablo 3). Let the player choose a difficulty right at the start, and then they're stuck with their choice for the entire campaign. The problem with sliders is that players encounter a boss they couldn't beat, and they turn down the difficulty instead of thinking of ways to overcome the encounter. It's lazy. It's also their prerogative to do so, but playing like that wastes the developer's effort in designing an encounter.
