D&D 5E What's your favorite two item combo?

[Saeviomagy]

Glyph of warding + teleport circle for a hilarious no-save trap
Demiplane + sequester for a demiplane that can never be accessed by anyone but you, because even you didn't look at the item that you sequestered within it.
Keen mind + teleport - because glancing at it now counts as familiar.
Keen mind + any illusion spell - because you can reproduce anything you have seen or heard

 

[Bardbarian]

Mounted combatant feat and Shield Guardian.