It's not just the spells themselves, but sometimes the combinations...
Glibness & Telekinesis (by charisma-based spellcaster):
Both from previous editions. The mechanics enable a beautiful synergy by RAW. Glibness lasts 1 hour (no concentration) and sets the minimum possible die roll for any charisma check to 15. Telekinesis is a spellcasting ability check vs strength check of target. So a good high-level combo for a Bard (taking Telekinesis from Magical Secrets) or a Sorcerer (Glibness from a Wish).
Demiplane:
Used to be an epic spell in 3.5 (also similar to 9th level spell, Genesis)? I think. Now it's an 8th level spell, perhaps not as cool in some ways, but available earlier and still has lots of potential. The big difference being it is an actual plane in its own right (PHB pg. 302).
Consider Demiplane & Plane Shift:
Create a unique demiplane, then plane shift your target to the demiplane. It's an early (and cheap) version of imprisonment. Plus you can prep the demiplane with 'fun' for the target to experience upon arrival. For example, fill it with water for targets that like to swim, place some magic mouths that trigger
the most annoying sound in the world, decorate the place like a party (for one) with a 6th-level version of Major Image, how about some Stinking Clouds (from a permanent Guards and Wards), maybe some Explosive Runes and Symbols, or just pack it full of undead... Who says imprisonment had to be boring? You can always plane shift more guests from time to time. Start a collection.