That's an interesting point about the PCE never being pushed to the max, it seems like every console except the PCE has at least one HOLY SHIT game that blows your mind by stretching the console beyond what you thought was possible. I can't think of one time I've ever been blown away by the PCE graphically, but I can think of quite a few Genesis & SNES games that really dominate the hardware. I'm not saying that I'm not impressed by the PCE since I think it pumps out some awesome graphics, I'm just saying that I've never been amazed by something that I didn't think the PCE was capable of.
EDIT* Actually the whole last level of Blood Gear was pretty amazing for the gigantic end boss and amount of sprites on screen, and Legend of Xanadu II is incredible looking with it's TONS of parallax.