Most disc-based games here are 7z archives with .bin/.cue in them. ;)
All game files are, by definition, roms. Also, I store my launchbox games in a giant folder called roms. My discs there are in fact all CHD except a few systems like CD32/CDTV.
Just trying to give you a mild heart attack :P
On topic: I don't have any games to add here - I'm sure they're already in the thread - but I wanna say I'm glad that Saturn emulation is great these days. It wasn't always great. I didn't play Shining Force III until like 2019. Same with Policenauts, which is better than PSX btw.
Some other games I tried out were Astal, Mystaria (aka Blazing Heroes) and Legend of Oasis, they were both pretty good for the first few hours but I didn't finish them for some reason.
Most of the popular Saturn games are shmups or other arcade games that i already had on MAME/PSX/etc. but there's definitely some other rare games worth playing
Edit: Forgot Saturn Bomberman, what the hell. How could I!? It's turned into my favorite Bomberman game, barely edging out SB5 on SNES. What an AMAZING soundtrack too.