Check notes for samples. Some of these aren't insane but they're good! Some of these might only have a few tracks that stand out. Since many of these did not get official soundtrack releases, I have gone with the title of the tracks in the game files if necessary.

Default sorting puts new additions at the top.

Adding more as I go.

<100 plays on Backloggd only (at time of addition).

Not on IGDB:
Unknown - Game B | Puzzle - Flowers and Patterns| NDS | 2009
Kazuhiro Kanae - Smoky Mountain Path | De.FaNa | PC-98 | 1995
Unknown - So Cool | Doukyu Re-Mix - Billiards Multiple | PS1 | 1999
Unknown - Artistic | World Billiards Tournament: Break Nine | Xbox | 2002
Zenji Nishikawa, Noriyuki Shindou - Gather Way! | Sion II: The First Attack | X68000 | 1992
Unknown - Be Cool! | Hyper Formation SOCCER | PS1 | 1995 | Suggested by BeachEpisode