This took longer than expected. I probably missed some secrets/samples so put 'em in the comments. Timestamps, extra samples, links to Neil's stuff, and FAQ below.
#mouthdreams

Timestamps (also in pinned comment):
Mouth Silence
0:00:00 - 1. Goodbye
0:02:17 - 2. Rollercloser
0:05:41 - 3. Furries
0:08:01 - 4. Friends
0:08:12 - 5. Best
0:12:05 - 6. Pokémon
0:15:07 - 7. Sexual Lion King
0:19:14 - 8. Crocodile Chop
0:22:56 - 9. Transmission
0:23:50 - 10. Love Psych
0:27:39 - 11. Orgonon Gurlz
0:32:03 - 12. Born to Cat
0:32:47 - 13. What Is It
0:35:51 - 14. It's
0:37:00 - 15. Close to the Sun
0:38:20 - 16. Numbers
0:43:31 - 17. Space Monkey Mafia
0:47:20 - 18. Wndrwll
0:50:49 - 19. Piss

Mouth Sounds
0:55:46 - 1. Promenade (Satellite Pictures at an Exhibition)
0:57:11 - 2. Modest Mouth
1:00:57 - 3. D'oh
1:02:52 - 4. Vivid Memories Turn to Fantasy
1:05:36 - 5. Bills Like Jean Spirit
1:10:21 - 6. Full Mouth
1:12:38 - 7. Alanis
1:14:00 - 8. Imagine All Star People
1:16:59 - 9. Imma Let It Be
1:19:03 - 10. Daft Mouth
1:22:10 - 11. Like Tears in Chocolate Rain
1:26:01 - 12. No Credit Card
1:31:07 - 13. Bega Interlude
1:31:32 - 14. Melt Everyone
1:36:25 - 15. The Sharpest Tool
1:39:03 - 16. Mullet with Butterfly Wings
1:45:25 - 17. Smooth Flow

Mouth Moods
1:51:54 - 1. The Starting Line
1:54:49 - 2. Floor Corn
1:57:17 - 3. ACVC
2:00:17 - 4. 300MB
2:02:29 - 5. Revolution #5
2:02:57 - 6. Dear Dinosaur
2:06:36 - 7. Annoyed Grunt
2:10:08 - 8. Bustin
2:13:55 - 9. Blockbuster
2:14:10 - 10. Busta
2:15:18 - 11. Tiger
2:18:21 - 12. The End
2:21:53 - 13. Shady Interlude
2:22:51 - 14. T.I.M.E
2:27:28 - 15. Smooth
2:31:46 - 16. Stand By Meme
2:34:11 - 17. Wallspin
2:37:26 - 18. Wow Wow
2:40:55 - 19. Mouth Pressure
2:44:39 - 20. Shit

Mouth Dreams
2:48:48 - 1. Yahoo
2:51:03 - 2. Mouth Dreams (Intro)
2:51:55 - 3. Spongerock
2:54:11 - 4. Just a Baby
2:58:00 - 5. Superkiller
3:00:26 - 6. Get Happy
3:04:16 - 7. Ribs
3:08:05 - 8. My Mouth
3:10:39 - 9. Aerolong
3:12:05 - 10. Sleepin' (Briefly muted)
3:13:20 - 11. Aammoorree
3:15:37 - 12. Where Is My Mom
3:17:51 - 13. Fredhammer
3:20:48 - 14. Limp Wicket
3:23:14 - 15. Cannibals
3:27:43 - 16. The Outsiders
3:28:56 - 17. Johnny
3:30:26 - 18. Closerflies
3:34:01 - 19. Nightmovin'
3:35:26 - 20. Whitehouse
3:37:19 - 21. Wah
3:38:15 - 22. Pee Wee Inc
3:40:51 - 23. 10,000 Spoons
3:44:14 - 24. Mouth Dreams (Extro)
3:45:59 - 25. Brithoven
3:47:08 - 26. Ain't

As promised in the video, the full sample list for The Starting Line:
Nine Days - Absolutely (Story of a Girl)
Barenaked Ladies - One Week
Smash Mouth - All Star
The Smashing Pumpkin - Bullet with Butterfly Wings
Foo Fighters - Best of You
Montell Jordan - This Is How We Do It
Talking Heads - And She Was
James Brown - I Got You (I Feel Good)
Prince - Kiss
MC Hammer - U Can't Touch This
Cake - The Distance
Sam the Sham and the Pharaoh - Wooly Bully
Talking Heads - Road to Nowhere
Carl Douglas - Kung Fu Fighting
OutKast - Hey Ya!
C+C Music Factory - Gonna Make You Sweat (Everybody Dance Now)

and Annoyed Grunt:
Theme to Home Improvement
Vocal samples of Tim Allen
Disturbed - Down with the Sickness
The Mixtures - The Pushbike Song
Annie Lennox - No More I Love You's
Phil Collin - In the Air Tonight
Mungo Jerry - In The Summertime
M.I.A. - Paper Planes
Korn - Freak on a Leash
Third Eye Blind - Semi-Charmed Life
Rammstein - Du hast
Mario Paint
Green Day - Basket Case
Van Halen - Runnin' with the Devil
Vocal sample of "Shikaka" from Ace Ventura: When Nature Calls

All credit goes to Neil Cicierega. I urge you to support him by pledging to his patreon.
  / neilc  

Other Neil Links:
http://www.neilcic.com
   / neilcicierega  
   / neilcicieregamusic  
  / neilcic  
  / neilcic  
https://neilblr.com/

FAQ:
Why is Mouth Silence first?
As stated at http://www.neilcic.com/mouthsounds/, Mouth Silence is a prequel.

Why didn't you include [insert secret/sample here]?
Probably because I didn't know or forgot.

Why is it that time that [insert sample] appears is incorrect?
I just didn't realize it was incorrect.

How dare you?
While that is a rhetorical question, it is a very fair one to which I have no answer.