It depends somewhat on how you’re planning to watch it all. If you’re sailing the high seas or watching blurays you already bought years ago, just go until it starts to feel dumb again. But if you are going to pay real money or spend streaming subscription time, don’t watch any of it. Weiss and Benioff did such a bad job in handling the end that the entire series should be considered financially toxic. Not a penny, not a groat.

A better plan would be to listen to the audiobooks and hope that some residuals will help GRRM focus his ADHD long enough to finish another book while he’s still alive.

I did a rewatch last year and I think the best option is to just watch it all.

Season 1-4 are top tier. Season 5 is where the cracks start (Dorne adventures), but season 5 also has the benefit of being an ending of sorts (Jon dying). So stopping at 5 is an option.

Season 6 has a lot of great moments, Hold the Door Hodor, the destruction of the great Sept, the Battle of the Bastards and the Tower of Joy. So there is a lot to enjoy.

Season 7 is Dany finally arriving in Westeros and setting up everything in preparation for season 8. So if you're watching this season, then you should also watch 8. If you want to imagine your own ending, then maybe stop before this season.

I think seasons 7 & 8 gives us a solid ending for Theon and Jorah. We get the knighting of Brienne. There are other storylines that have their moments, but some of it is unfortunate since we know it doesn't go anywhere.

Just 1-4

If you put any stock in IMDb ratings, this may be useful to evaluate each season: https://seriesgraph.com/show/1399-game-of-thrones

I'd skip both 7 and 8 personally, that's about where I felt like I was forcing myself to watch

Everything else was pretty solid up to that point

I look forward to the day when there is a fan re edit of the show, hopefully the book ending is out by then… one can hope…

Honestly, all the way up to S08E02, then just pretend that everyone died in the battle of winterfell.

It did drop off a bit after S04, but it was still a good series after that.

I bought seasons 1-6 on Blu Ray with the assumption that I would end a rewatch there. That was a few years ago, and I still haven't done it though. It's a good place to stop cuz that's when Dany leaves Esos, Arya finished her House of Black and White stuff, and Jon's story of the knights watch ends.

I guess I'm a sucker for zombies. I'd definitely dip my toes into 8 until the fight. As an action sequence, it's pretty good. That or cut it early around mid way I guess.