On Linux or Windows? Firefox + uBlock origin (there’s nothing better than that)
On Mac? Firefox + uBlock origin (worse alternative: Safari + AdGuard, since you might synch browser with iPhone)
On Android? Firefox + Privacy Badger + uBlock Origin
On iOS? Safari + AdGuard + Vinegar + Baking Soda
On SmartTV it’s different.
Hardest overall solution that even works on PS5, Switch and other consoles: Get yourself a Pi-Hole https://pi-hole.net/
For WebOS TVs use this: https://github.com/webosbrew/youtube-webos
Android TVs should get SmartTube: https://github.com/yuliskov/smarttube#smarttube-old-name-smarttubenext
RokuTVs got either this thing: https://channelstore.roku.com/en-ca/details/840aec36f51bfe6d96cf6db9055a372a/playlet or the open source alternative: https://github.com/iBicha/playlet
PiHole unfortunately doesn’t work against YouTube ads - at least it never worked for me. It’s good for everything else tho. You would have to use ublock origin on desktop and an alternative YouTube client (like newpipe or grayjay) on mobile