Oh boy a difficulty level opinions thread
From hardest to easiest on Lunatic, UFO excluded because I haven't played it:
S1: Yamame, Yuyuko, Minoriko, Letty, Rumia, Wriggle
S2: Kyouko, Hina, Chen, Parsee, Mystia, Cirno
S3: Yuugi, Alice, Keine, Nitori, Yoshika, Meiling
S4: Satori, Aya, Laserball lady, Marisa, Patchouli, Prismrivers
S5: Orin, Sanae, Sakuya, Youmu, Arrow lass, Reisen
S6: Remilia, Kanako, Kaguya, Eirin, Yuyuko
Reimu exclued because I use Border Team, Miko excluded because I've never fought her legitimately, Utsuho excluded because I haven't hit her in a real run yet. Also keep in mind I only 1cced MoF, TD, and EoSD last month so I'm not nearly as familiar with them as I am PCB and IN.
Edit: wups extra stages
Extra: Koishi, Mamizou, Nue, Flandre, Suwako, Yukari, Mokou, Ran