The Thing (2002) did a great job with the whole fear aspect. It made you rely on your AI comrades, because you had certain roles to fill like medic and engineer. And if you wanted to make progress, you had to keep them alive. Also you had to keep them calm, if they saw something that freaked them out, they would literally kill themselves. So you had to do little things like trade ammo with them, give them a sedative, or prove that you weren't The Thing. Also you never knew when one of your team mates was going to be The Thing, or when they would transform. And it was truly random. You could play through the same part again, and one of your team mates might not change. It kept things dynamic and challenging.