@S E P H I completely forgot about the PSP, Vita games, and the MGS5 demo called Ground Zeros. Unlike other demos, Ground Zeros is actually a little preview game to MGS5 that's completely cannon, and you should play that before 5. "Portable Ops" and "Peace Walker", both of these games, are cannon. They're fun games, especially Peace Walker, but are very different from the mainline series. They feel very much like a mobile game in the way the missions are set up, and can be kinda grindy. So you might want to watch a summery video on those as well. They both slot in after MGS3 chronology, but release wise it's MGS3, Portable Ops, MGS4, Peace Walker, Ground Zeros, MGS5.
And if we're talking games that are cannon story wise. There's also Revengeance and Acid. I never played Acid. It's a turn based card game that takes place after 4. Revengence is the game furthest in the series and is an action slasher made by Platinum games, but with Kojima's involvement. It's off the rails crazy and very hilarious. This game can be enjoyed anytime after 4. It's cannon and takes place pretty far in the future, but they never really reference what happened in the other games, other than 2 and 4.
And if we're talking games that are cannon story wise. There's also Revengeance and Acid. I never played Acid. It's a turn based card game that takes place after 4. Revengence is the game furthest in the series and is an action slasher made by Platinum games, but with Kojima's involvement. It's off the rails crazy and very hilarious. This game can be enjoyed anytime after 4. It's cannon and takes place pretty far in the future, but they never really reference what happened in the other games, other than 2 and 4.