Yeah, the most important thing is to have fun.
If you don't mind darker themes (rape, snatching someone else's lover, subjugating someone through sex) then I suggest reading BISHOP's titles
https://vndb.org/p215. BISHOP specializes in cheerful rape stories, if that makes sense. Don't expect much in the story department though.
Some standouts:
- Mesu Kyoushi series (
https://vndb.org/v4153,
https://vndb.org/v4094,
https://vndb.org/v11916,
https://vndb.org/v16104)
- Gakuen 3
https://vndb.org/v5033
- Sansha Mendan
https://vndb.org/v6357
- Yakata
https://vndb.org/v12995 (this one doesn't have school setting, but it's one of BISHOP's best)
Also try:
- Ai Shimai IV
https://vndb.org/v14826
- Sei Estella Gakuin
https://vndb.org/v12037 (kind of like Bible Black with cults and supernatural powers).
- Verethragna
https://vndb.org/v16925 (more like Yu-Gi-Oh than Bible Black, but it's great).
- Walkure Romanze series
https://vndb.org/v/all?sq=walkure+romanze (guilty of trying too hard to sound cool at times, but the h-scenes are generally great)
- Yomi ecchi
https://vndb.org/v13852
- Kresnik
https://vndb.org/v2675 (Lilith is better at darker stuff, but this one is decent)
- Kimi no Mana wa Rina Witch
https://vndb.org/v18348 (same as above)
I probably should also mention Meikoku Gakuen (
https://vndb.org/v18795) and its sequel (
https://vndb.org/v23985), but I haven't read them.