Usually I don't care about graphics, as long as they serve their purpose (telling me what's happening in the game).
pixelly 2D is fine, perfect 3D as well, and anything in between really.
With the exceptiopn of what I would call "awkward 3D". 3D graphics that just exist just to make it 3D, without really adding anything to the game (or, in the case of Monkey Island 4, even making it quite hard to handle). I'm not talking about 2D gameplay in 3D graphics in general (New Super Mario Bros pulled that off great), I'm talking about companies almost making a 3D game, even if 2D would have worked as well and looked better. It mostly happened during the introductory phase of 3D gaming, with 3DFX, Direct3D and probably several more systems struggling for dominance, and games having jagged, badly-textured 3D models.
It was ok, as long as nothing organic was involved (Battlezone looked pretty good actually. The one with the biometal, not the arcade game)