A Crack in Time would be my favorite. Followed by R&C 2016.
Havent played Rift Apart, but im very much looking forward to. I hear only good things about it.

Tools of Destruction was my first Ratchet game so it holds a lot of sentimental value for being first for me. That being said A Crack in Time is my favorite and is the 2nd game that I ever platinum-ed after Uncharted 2.

Crack in Time is my favorite, the bonus time puzzles were excellent, wish there were more. I only didn't platinum the game because I sucked at the arcade machine mine game, one trophy left.

No PS5 yet, so no Rift apart yet.

A Crack in Time is my favorite followed by Up Your Arsenal.

Don't have a PS5 yet so i can't play Rift Apart yet. But from what i've seen it looks very good.

I say Crack in time. Sony platforms are Spyro and Crash( i try Sly Cooper and Jax and Daxter too, but don't work for me either) 

don't play the Ps5 game yet. 

History might swap this around a bit but Rift Apart is currently my favourite. I felt the gameplay was the most refined, the worlds were the prettiest, the story was the best, and I totally have a crush on Rivet. The side content was pruned a bit - which I prefer, because the core shooting gameplay loop is why I play Ratchet & Clank, not the puzzle solving.

Crack in Time is #2, followed by Up Your arsenal and Going Commando, then the 2016 Remake (Because it's basically the story of #1 with the gameplay of the most recent games). 2002 hasn't held up as well as the other games but I still love it.

Might be an unpopular opinion... But the first one is my favourite, followed closely by the third one. The second one was very good too.

The PS3 ones were not quite on the same league as the original PS2 trilogy (although they were still good games and very enjoyable), the 2016 reboot was an absolute pile of garbage... And I don't have a PS5 so no Rift Apart yet.

I've liked all that I've played, with 2016 probably being my favorite.

Note that I accidentally voted Rift Apart in the poll, but I haven't played it.

All 4 One

Granted its nowhere near the level of quality as the main games but my friends are I are suckers for couch coop.

This is the only one i've not gotten the platinum on.