I've had the most gobsmacking moments in Skyrim. Walking up a rocky stream under a full moon, with a low level, when suddenly a sabre cat attacks me. We have an intense battle that leaves me on the brink of death, but concludes with a "kill" animation of me smacking it with a mace and knocking it down a cliffside into the water, full moon and aurorae in the background. I seriously sat there in shock for like 5 seconds. Perfect video game moment.