No problem. I like making lists for Namor.
Plus, it's fairly easy, since I'm using the Comic Book Database for this thread anyway.
Some of these may be cameos or flashbacks.
Fantastic Four (1961)
Annual 01 - 'Sub-Mariner Versus The Human Race!'
Annual 11 - 'And Then the Invaders!'
Annual 22 - 'Atlantis Attacks'
Annual 25 - 'In Kang's Clutches!'
#4 - 'The Coming of... Sub-Mariner!'
#6 - 'Captives of the Deadly Duo!'
#9 - 'The End of the Fantastic Four!'
#14 - 'The Merciless Puppet Master'
#27 - 'The Search for the Sub-Mariner'
#33 - 'Side-By-Side With Sub-Mariner!'
#102 - 'The Strength of the Sub-Mariner'
#103 - 'At War With Atlantis!'
#104 - 'Our World -- Enslaved!'
#147 - 'The Sub-Mariner Strikes!'
#148 - 'War on the Thirty-Sixth Floor!'
#149 - 'To Love, Honor, and Destroy!'
#154 - 'The Man in the Mystery Mask!'
#190 - 'The Way It Was'
#194 - 'Vengeance is Mine!'
#195 - 'Beware the Ravaging Retrievers!'
#219 - 'Leviathans'
#260 - 'When Titans Clash!'
#261 - 'The Search For Reed Richards'
#278 - 'True Lies'
#319 - 'Secret Wars 3'
#324 - 'I Die Like the Stars!'
#400 - 'Even the Watchers Can Die!'
#401 - 'At the Mercy of Maximus'
#402 - 'By Our Friends, Besieged!'
#403 - 'Things to Come!'
#404 - 'With Friends Like These -- !'
#405 - 'Terror is Tomorrow!'
#406 - 'Doom Quest!'
#407 - 'Reunion!'
#408 - 'Unbeatable is My Foe!'
#410 - 'The Ties That Bind!'
#411 - 'Black Bolt -- Berserk!'
#412 - 'Settling the Score with the Sub-Mariner!'
#413 - 'Missions: Impossible!'
#416 - 'Unfinished Business'
#525 - 'Dream Fever, Part 1'
#536 - 'The Hammer Falls: Part 1'
#543
#551 - 'Epilogue, Chapter One: The Beginning of the End'
#552 - 'Epilogue, Chapter Two: The Middle of the End'
#569 - 'Doom's Master, Part Four of Four'
#584 - 'Congratulations, Mister Grimm. You're Handsome Again!'
#585 - 'The Kings of Atlantis!'
#586 - 'World-Eater!'
#587 - 'The Last Stand!'
#588 - 'Epilogue: Month of Mourning/Uncles'
#600
#604 - 'Forever, Part 5'
#642 - 'Back in Blue Part 2'
#643 - 'Back in Blue Part 3'
Fantastic Four (1998)
#6 - 'The Cruelest Month'
#27 - 'Say -- What?!'
#32 - 'Abyss'
#41 - 'Marooned'
#42 - 'A Clear & Present Danger'
#43 - 'And the Walls Came Tumbling Down'
#44 - 'Annihilation!'
#47 - 'Just Imagine...'
Fantastic Four (2014)
#3 - 'The Fall of the Fantastic Four Part Three'
#5 - 'The Fall of the Fantastic Four Part Five'
#13 - 'East of Eden, Part Five'
#14 - 'Back in Blue, Part 1'