Just finished playing through portal. It was the most enjoyable ending and credit sequence i’ve ever seen in a game, and I’ve played a lot of games!
The antagonist computer chick was also one of the best characters in a game so far. Leave it to Valve to come up with a great story, and involving exactly zero human characters (although that might be “Blade Runner” style debatable!) Without giving any spoilers, i liked the style of the puzzles/challenges in the last half of the game a lot more than those at the beginning half, probably because of the things the computer was saying.
I also played it on both the 360 and PC. The 360 was more comfortable on the big couch with the 50″ HDTV, but the pc version had a little better control. Some of the puzzles required a pretty good aim with very limited time to make mistakes. If you have a PC that can handle it, get that version. If you’re a 360 achievement whore, then get the XBOX version :D. If you have something like GameFly, buy the PC version and rent the 360 one!
Update: The guy who wrote the song in the credits (Jonathan Coulton) has posted a blog post about how the song came about, complete with lyrics (spoiler alert!) and chords. Now people are “youtubing” up their own cover versions. Thats how awesome it is!