I visit boredpanda.com
The content changes daily M-F. They usually post a cute or funny collection of photos at least twice a week.
This is the most recent. It helps when the days news gets too stressful.
Therapy dogs are a wonderful idea - here’s one cheering up children in hospital. 
Elsa brings smiles to patient families on Valentine’s Day - YouTube
By contrast, here’s a vulgar video (but I like it!):
When I need cheered up, I have a “go to” list of funny videos, some of which make me laugh out loud:
Pinky the Cat
Dog pays tribute to Kiss’ Gene Simmons
Zlad! - Elektronik Supersonik
Electric Six - Danger! High Voltage
Sonseed - Jesus Is My Friend (along with the parody Vader is my Friend)
Puddles Pity Party - Folsom Prison Blues/Pinball Wizard Mash Up
I love to watch reactions of millennials listening to my favorite songs. A lot of times I think they faking never hearing the songs before but the many astonished, “They’re white!” exclamations when listening to The Righteous Brothers or Hall and Oates seems genuine.
Adam Savage building something, and showing his sheer joy at the creative process, I can watch that kind of thing all day:
Other makers on youtube I like:
Mark Rober
Simone Giertz
Wintergatan
Colin Furze
Good Lord, does Adam look sexy in this picture!
Makers I love that make me happy
Peter Brown
Ben’s Worx
Nick Zammeti
Did you see him in his much younger days, in the Charmin commercial?
I have seen every Mythbuster episode several times and, for sure he was an aggressive ginger. He aged like cheddar though, as this video demonstrates.
I’m obsessed with this animal voice over channel. The shorts are funnier than the longer episodes. Most of the videos are safe for work. https://www.youtube.com/@rxckstxr
How about the guy who plays piano for his cats?
This channel has a lot of shorts. He starts playing piano in a public space and people start joining in.
The surprised reaction from the public always makes me smile. Reminds me that gathering around a piano and singing used to be common. Especially in bars.
I still havent figured out how to link to YouTubes, but-
Louis Armstrong - What A Wonderful World
Lord of the Rings | The Shire - Music & Ambience
You’ve Got A Friend In Me - Quarantined Music Video with a 19 Piece Big Band! (Disney Cover)
Showstopper 
Guys and Dolls 1955 Sit Down, You’re Rockin’ the Boat - YouTube
See the way Bruce Springsteen looks at Chuck Berry - one star to another.
The amazing Patrick Bartley :-
and
Just in time for Halloween:
Key and Peele, “White Zombies”
and a couple of guys reacting to the video:
Fuck Jerry TV, always gets a laugh from me. All their content is owned or licensed.
I like watching Great Big Sea music videos. They’re lively, fun and good music.
https:// www.youtube.com/watch?v=-wcjBU8zbdY
Just wanted to say thanks for this recommendation. I have been absolutely loving this series; the most consistently funny show I’ve seen in ages.
I can’t find this on Youtube, only on…TikTok.
A school had “teachers dress like the students” day and had fun filming. I am a teacher and this may work more for teachers, but I assure you this is EXACTLY how it is today in schools with kids.
It’s truly incredible, one of my favorite shows.