such an old thread D: not sure whether there's a current one? i definitely want to somehow share my favorite maps (not songs). I'll also add which difficulties i like since i don't know whether all dificulties are as nice as those ones.
again. it's not because of the songs, but because of the maps. if it had to be a mix of both i'd probably also consider https://osu.ppy.sh/s/326121 (Eluveitie - Isara).
My favorite song and favorite best map are completely different. My favorite Osu! Song is probably Reol - Monster but my favorite beat map is probably Ensou ft. Gumi - Coma.