We've seen solid gameplay from Heavy Rain, an entire side level was display as the tech demo and we know roughly what the control will be like (R1 is to walk for example). The atmosphere of the side story is ACE and if the main game has a longer story and equally involving story then I'm sold. I also love the feature being taughted where if the main character dies, the game continue and you somply switch to another of the cast, that would be so awesome if pulled off the right way.
Alan wake also look fantastic, but we've seen nothing of the gameplay itself so I'll hold my tongue until more substance is revealed. I hope the PC version isn't just a direct poorly executed port, I'd like it to have some good optimization because I'm certain the grapihc would be even better on a decent PC.