There's certainly plenty to choose from. But I think adding episodes just because the crew are acting weird stretches the theme too much.
Altered Realities
Shockwave
Shockwave, Part II
Twilight
E2
Storm Front, Part I
Storm Front, Part II
In A Mirror, Darkly Part I
In A Mirror, Darkly Part II
The Alternative Factor
The City on the Edge of Forever
Mirror Mirror
Yesterday's Enterprise
Remember Me
Future Imperfect
The Inner Light
Tapestry
Frame of Mind
Parallels
All Good Things...
Crossover
Visionary
Through the Looking Glass
The Visitor
Hard Time
Shattered Mirror
Things Past
Children of Time
Far Beyond the Stars
The Emperor's New Cloak
Non Sequitur
Deadlock
Coda
Before and After
Year of Hell
Year of Hell, Part II
Timeless
Endgame, Part I & II
Bizarre, Out of Character, possessed or drug induced, nightmares & traumatic stress
ENT: Strange New World, Singularity, The Crossing, Vanishing Point, Bounty, Impulse, Hatchery, Observer Effect, These Are the Voyages... (heh, sorry couldn't resist!

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TOS: The Naked Time, The Enemy Within, The Return of the Archons, This Side of Paradise, Amok Time, The Paradise Syndrome, Day of the Dove, The Tholian Web, Turnabout Intruder
TNG: The Naked Now, Lonely Among Us, Datalore, Conspiracy, The Schizoid Man, Hollow Pursuits, Sarek, Brothers, Clues, Identity Crisis, The Host, The Mind's Eye, The Game, Conundrum, Power Play, Phantasms, Genesis
DS9: Dramatis Personae, Whispers, Distant Voices, Facets, The Assignment, Empok Nor, The Reckoning
VOY: Cathexis, Projections, Persistence of Vision, The Chute, Remember, Warlord, Blood Fever, Darkling, Worst Case Scenario, Demon, Living Witness, In the Flesh, Latent Image, Course: Oblivion, The Voyager Conspiracy, Memorial, Workforce, Workforce, Part II, Author, Author