It always throws me off. In a dorky 80s looking game, I never care about "realism" but I hate when you play a game that has super realistic graphics.. and then find a room full of health packs on the floor or some other obvious game contraption.
Yeah, it's similar to the 'uncanny valley' principle.
Still, gorgeous looking games are great, but if I wanna play some I turn on my PS3 or something. If a game plays fine and it doesn't look outright ugly, no problem.