This isn't ranked exactly since many of them are ties, but it's close enough. (I haven't played Okami or Prince of Persia: Sands of Time yet, and I fully expect them both to make it onto this list. As well as probably a number of unexpected games that will surprise me with how good they are, like The Walking Dead did.)
1. Silent Hill 2
2. Journey
3. Riven
4. Guild Wars 2
5. Final Fantasy XI
6. Botanicula
7. Machinarium
8. Aquaria
9. Ico
10. The Walking Dead
11. Dragon Age: Origins
12. Pixie Hollow (don't judge, it's excellent for what it is)
13. Secret Paths to the Sea (nostalgia)
14. Secret Paths in the Forest (nostalgia)
15. Uru
16. Star Wars: The Old Republic (yes, I enjoyed the Imperial Agent story more than any other KOTOR story, and more than Mass Effect)
17. Logical Journey of the Zoombinis (nostalgia)
18. Nelda Nockbladder's Anatomy Lesson (nostalgia)
19. Silent Hill 3
20. Portal 2
FYI, if any of you post a list with a number of my games on it, I will stalk your list for other games I might enjoy. (Casual Shinji and Mikeyfell, I'm looking at you.)
1. Silent Hill 2
2. Journey
3. Riven
4. Guild Wars 2
5. Final Fantasy XI
6. Botanicula
7. Machinarium
8. Aquaria
9. Ico
10. The Walking Dead
11. Dragon Age: Origins
12. Pixie Hollow (don't judge, it's excellent for what it is)
13. Secret Paths to the Sea (nostalgia)
14. Secret Paths in the Forest (nostalgia)
15. Uru
16. Star Wars: The Old Republic (yes, I enjoyed the Imperial Agent story more than any other KOTOR story, and more than Mass Effect)
17. Logical Journey of the Zoombinis (nostalgia)
18. Nelda Nockbladder's Anatomy Lesson (nostalgia)
19. Silent Hill 3
20. Portal 2
FYI, if any of you post a list with a number of my games on it, I will stalk your list for other games I might enjoy. (Casual Shinji and Mikeyfell, I'm looking at you.)