ME2 had the best cutscenes I've ever seen in a game. The script was good, they always served a purpose, the interaction was never far from the forefront and they were directed with a good sense of pace and drama. I also loved that the parts that were pre-rendered looked similar to the in-game engine, but just more glossy. One of the only mis-steps in ME2 was where - once or twice - it broke the rule about not showing characters do things they can't do in the rest of the game. When Jack escapes from her shackles, she destroys two heavy assault bots with one giant biotic blast - why couldn't she do that later on, when it would have been useful? I don't much care for the HL2 approach. It's debatable whether it even uses "cutscenes" at all, since the story moments in HL2 don't cut away from the gameplay. However, they do have a tendency to just lock you in a room while a guy talks at you, even when you're running around and climbing on his furniture. It just looks stupid, and I don't feel like it's keeping me immersed.