Half-Life 2, episode 1, was so fun to revisit. It's incredibly manic; there isn't as many varied environments, but I absolutely love the citidel scenes and getting everyone to the train; it felt like a full battle for liberation. It's really fun, and I first played it on the orange box, but it's better on the PC. Gordon and Alyx get to have a more intimate relationship; you're together more, and I really like the character development; she's such a great character. Oh yeah, and dog is still my good time boy.