I've gotten several HD collections now. I started with Metal Gear Solid which has MGS 2, 3 and Portable Ops. It's ok, not wonderful, but I just wanted to way to play MGS 3 again and again. Next I tried the Silent Hill HD collection consisting of Silent Hill 2 and 3. I was VERY underwhelmed by that. I think Silent Hills just were never that great of games to begin with. Ico and Shadow is the best collection that I've played so far. Ico does not really hold up that well. There is still a lot I admire about the game, but it's just not really all that fun to play anymore.
Ico is a really atmospheric game where you control a little boy who is left to die in a HUGE ancient castle. Along the way he meets a strange girl who is being chased by shadow creatures and is also a prisoner in the castle. You attempt to escape from the castle by navigating a bunch of puzzles while dragging your new friend around by the arm. What makes this game a classic is it's very non-traditional approach. There is no HUD to the game, so no menus, no life bar, no super-power meter, nothing. Its just you and the environment on-screen. There's very little music in the game also. Much of the time all you have for audiological company is the echoing of the boy's footsteps and gusting wind on the exterior areas of the castle. All in all Ico is a very interesting place to visit, but after all these years it's become sort of a 1 trick pony. It's is definitely worth checking out if you have never played the game before.
Onto the main event, Shadow of the Colossus. This game holds up completely. Since I got my PS3 this is probably the game I've spent the greatest amount of time with. A game that I already finished multiple times back on PS2.
The whole game consists of little more than 16 boss fights. Between the boss fights you need to go out and explore a large and very well designed world. Ico and Shadow both succeed in giving their respective worlds a very real, almost tactile, feel. In Shadow the design of the world is second only to the design of the Colossi. Most of the colossi are these towering monsters that you need to climb up and stab in certain "weak points". Each colossus is like a complete level or environment on its own and each one has different behavior and tricks you need to do to take it down so that fight also has an element of puzzle-solving to it.
Unlike Ico, Shaodw of the Colossus makes use of music a lot more. Not only is the music all very good, the soundtrack also changes dynamically as you fight the colossus. Meaning that as you're fighting a boss the music will switch tracks, usually smoothly enough to not draw unpleasant attention to itself, so that when you piss off the colossus by stabbing it in the face it will start to thrash its enormous body around. While you're holding on for dear life a really exciting and epic song will start to play.
Shadow of the Colossus, and Ico in it's own way, were both benchmarks in game development. You don't see a whole lot of games like these, but I think they both left their respective marks on game development and there will always be diamonds in the rough striving to be more like these games. At least I hope so.