I’ve always found it difficult to rank music like this since I tend to listen to different music depending on mood. However, there’s one song that has stuck with me since I listened through it the first time like 8 years ago: The Great Escape - Seventh Wonder.
It’s a 30min song based on the poem Aniara by Harry Martinson and I love it to bits.
I think the ones I’m most proud of are beating Journey of the Prairie King in Stardew Valley and the 100% achievements in Spelunky HD and Spelunky 2. Grinded several hundred hours for those