I agree - utterly blown away by the game when I played it last year. I recently picked up the soundtrack, because I love the music.
What's your favourite Colossus? I think mine is a toss up between 3 (the utterly massive one with the big stone sword) and 5 (the first bird one). I reckon I'm leaning towards the bird one. The build up is superb, swimming across the lake with the colossus on that big pedestal watching you, and it was so exhilarating flying through the air on its back.
Everything about that Colossus is incredible. The area surrounding the lair is so well designed and it's real treat to explore.
The moment when when Colossus first spies you, and lets out that screech before swooping at you is one of the best moments in gaming. When you cling on and the music starts to kick in, it's the most heroic feeling. I've never experienced such a feeling from a game before.
Simply blown away by the game. I can barely remember the details of many of the Collossuseseses. The exploration that you would expect to be tedious isn't because you know that when you find what you're looking for it'll be worth it. And I never felt like puzzles were recycled at any time.