46 cards where the text includes “choose not to untap”

Amber Prison (Classic Sixth Edition #272)
Ashnod's Battle Gear (Fourth Edition #296)
Bottomless Vault (Fifth Edition #411)
Callous Oppressor (Onslaught #72)
Coffin Queen (Tempest Remastered #87)
Deserter's Quarters (Journey into Nyx #160)
Dwarven Hold (Fifth Edition #414)
Endoskeleton (Urza's Saga #294)
Entrancing Lyre (Theros Beyond Death #233)
Everglove Courier (Onslaught #262)
Flamestick Courier (Onslaught #203)
Flowstone Armor (Nemesis #131)
Frightshroud Courier (Onslaught #149)
Ghosthelm Courier (Onslaught #85)
Giant Oyster (Time Spiral Timeshifted #22)
Grand Marshal Macie (Unfinity #168)
Hedge Whisperer (Murders at Karlov Manor #165)
Helm of Possession (Tempest #291)
Hisoka's Guard (Champions of Kamigawa #68)
Hivis of the Scale (Mirage #182)
Hollow Trees (Fifth Edition #418)
Icatian Store (Fifth Edition #419)
Ice Floe (Masters Edition II #232)
Immovable Rod (Forgotten Realms Commander #7)
Mana Leech (Urza's Saga #141)
Mole Worms (Fifth Edition #179)
Old Man of the Sea (Masters Edition III #45)
Pearlspear Courier (Onslaught #48)
Phyrexian Gremlins (Antiquities #18)
Preacher (Masters Edition #24)
Rubinia Soulsinger (Commander Anthology #191)
Rust Tick (Scars of Mirrodin #198)
Sand Silos (Fifth Edition #423)
Sand Squid (Mercadian Masques #96)
Seasinger (Masters Edition #49)
Spirit Shield (Fallen Empires #90)
Tawnos's Coffin (Masters Edition #169)
Tawnos's Weaponry (Masters Edition IV #232)
Thalakos Dreamsower (Tempest #92)
The Blackstaff of Waterdeep (Adventures in the Forgotten Realms #48)
The Pandorica (Doctor Who #25)
Thran Weaponry (Urza's Legacy #135)
Vedalken Shackles (Modern Masters #218)
Whip Vine (Alliances #103a)
Willow Satyr (Masters Edition III #139)
Zelyon Sword (Fallen Empires #91)

This search is finished. Now the real work can begin.