One of my favorites is Aurora from Gunbound, which I use as my Treasure Vault/Casino music:

https://www.youtube.com/watch?v=062dT-Qbokg

Feel like it fits Treasure Vault better, it just feels happier, brighter, and more fun.

Other tracks I use are FF8's boss theme, "Force Your Way", for boss fights like Vana and Twins, and two tracks from Star Ocean 4: "Blood on the Keys" for Battle Theme 1, and "Don't Be a Hero" for the pre-boss brawls, such as the fight right before Sovereign Slime.

https://www.youtube.com/watch?v=JqVfZyLSrpY

Also I use this for the floor clear music upon reaching the elevator:

https://www.youtube.com/watch?v=gFXegRD0uJ8