Expanding on what has already been mentioned, bundles of DRM free games overall are usually pretty rare.

One exception would be Itchio, where DRM free game bundles are plenty, but they're usually games people wouldn't be buying normally (many very indie/beginner projects there), so preople would need to curate these bundles to see what's worth posting here.

And there's also the risqué game bundles from Groupees and IndieGala that so far have been mostly DRM free, but it's complicated to share adult stuff here without breaking the forum rules. (people may want to ask the mods how much is accepted as long as the post is within the context of the thread)

Platinum Collection: Build your own Bundle (August)    (Fanatical)
 
 
3 for $9.99 ($12.49 CAD)   ⁞   5 for $15.99 ($19.99 CAD)   ⁞   7 for $19.99 ($24.99 CAD)
 
 
AI War 2
Assassin's Creed – Director's Cut Edition  (Uplay)
Assassin’s Creed Brotherhood  (Uplay)
Assassin's Creed Revelations  (Uplay)
Battle Royale Tycoon
Blacksad: Under the Skin
Edna & Harvey: The Breakout – Anniversary Edition
Flashing Lights: Police Fire EMS
Heliborne – Enhanced Edition
Paw Paw Paw
Rayman Origins  (Uplay)
Remothered: Broken Porcelain
Rock of Ages 3: Make & Break
Samorost 3
Seven – Enhanced Edition
Shadowhand: RPG Card Game
Size Matters
Thief
Tomb Raider – Game of the Year Edition
Warhammer: End Times - Vermintide

if you bought Syndicate and Ultima Underworld just before EA requested removal in June, you can now refund them to get them for free:

Source:
https://www.pcgamer.com/ultima-underworld-and-syndicate-return-to-gog-and-now-theyre-free/

Has gog complained about those? I don't recall them ever complaining about links from there. I've assumed people don't share groupees links as their games are usually as bottom quality as itch.

It's actually in their Forum Code of Conduct: But when I asked one of the mods about a very specific situation regarding posting mature stuff, he/she said it should be ok, as long as the source wasn't linked directly and no images or innapropriate messages were included in the post. But since it was a very specific situation, I can't be sure what's the threshold between allowed and not allowed.

Build your own Bumper Bundle   (Fanatical)
 
 
1 for $1 ($1.25 CAD)   ⁞   5 for $2.99 ($3.75 CAD)   ⁞   10 for $4.99 ($6.25 CAD)
 
 
ATV Drift & Tricks
Beat Cop
bit Dungeon
Brawlout
CATch the Stars  +  CATch the Stars: Japan   (2 games)
Cat Quest
Chaos Reborn
Hidden Memory: Neko's Life  +  Hidden Memory: Nature   (2 games)
Hue
Internet Cafe Simulator
Kyn
Mana Spark
Meow Lab  +  Kittens and Yarn   (2 games)
Narcos: Rise of the Cartels
OPUS: Rocket of Whispers
Rogue Stormers
Savage Lands
Smoke and Sacrifice
The Little Acre
When Ski Lifts Go Wrong

Humble Big Brain Bundle
 
 
$1 or more  ($1.25 CAD)

I am not a Monster: First Contact
No Time to Relax
 
 
Beat the average

5D Chess With Multiverse Time Travel
7 Billion Humans + Soundtrack
The Battle of Polytopia
 
 
$9 or more  ($11.26 CAD)

BattleTech
XCOM 2
XCOM 2: Reinforcement Pack  (DLC)

Savage Lands is definitely worth $1.25.

Humble Jackbox Summer Party Bundle
 
 
$1 or more  ($1.25 CAD)

You Don't Know Jack - Volume 1 XL
You Don't Know Jack - Volume 2
You Don't Know Jack - Volume 3
 
 
$15.00 or more  ($18.75 CAD)

The Jackbox Party Pack 3
The Jackbox Party Pack 4
 
 
Beat the average

Drawful 2
Fibbage XL
Quiplash
The Jackbox Party Pack
The Jackbox Party Pack 2
You Don't Know Jack - Headrush
You Don't Know Jack - Movies
You Don't Know Jack - Sports
You Don't Know Jack - Television
You Don't Know Jack - Volume 4: The Ride
+ 40% off The Jackbox Party Pack 7
 
 
$20.00 or more  ($25 CAD)

The Jackbox Party Pack 5
The Jackbox Party Pack 6

These games also include DRM free builds when you buy them from the bundle:

I am not a Monster: First Contact
5D Chess With Multiverse Time Travel
7 Billion Humans + Soundtrack

A bummer that the YDKJ games aren't DRM free (at least they're not listed as such in the bundle) as I'm fairly certain that bought outside of the bundle they're DRM free

Yes, the complete series is offered DRM-free on the Humble Store, but all the games in the current bundle seem to be Steam only.

Fanatical Kingdom Bundle

€1
Giana Sisters 2D
Kill to Collect
Rad Rodgers Radical Edition

€2.99
Bang Bang Racing
Giana Sisters: Twisted Dreams
Giana Sisters: Twisted Dreams - Rise of the Owlverlord
Sine Mora EX
SkyDrift
SPITLINGS

€4.99
Aces of the Luftwaffe - Squadron
Jagged Alliance: Rage
Townsmen - A Kingdom Rebuilt

Humble Seven Deadly Sims Bundle
 
 
$1 or more  ($1.25 CAD)

Bridge Constructor Portal
 
 
Beat the average

Police Stories
theHunter: Call of the Wild
Total Tank Simulator
 
 
$12 or more  ($15 CAD)

Ancestors: The Humankind Odyssey
Lobotomy Corporation: Monster Management Simulation
Tank Mechanic Simulator

Hot Fantasy Bundle, from IndieGala

7.99 USD for 6 DRM free games (all NSFW).

Price will increase on August 21, 12 PM UTC, Unsure how much it'll cost when the price increases.

Also unsure right now about when the bundle will end.

According to ITAD, the bundle includes 3 games that were never bundled before, and 3 rebundles.

Not linking the bundle here per recommendation of a moderator regarding a previous post with similar circumstances.