Doom3 is gonna be creepier though. That's what id is shooting for... less monsters, more powerful and creepy ones, and the environmental lighting, effects, and rendering look awesome... if Valve were told to make the game for Doom3, it would be great.
... BUT, look at Half Life, the Piers, the Country Road, the City scenes, they all look fantastic, and way more realistic than Doom3 ever will.
Doom3 has a great Sci-Fi look to it, but the half life 2 physics engine is totally realistic ( the steel drum pachinco machine demo with the pool owns).