I liked 4, it’s very much a victim of being a Ubisoft game though, as in it’s more of the same. I’d say the only difference is the setting.

5 is similarly pretty good, I feel like it removed a lot of the “Guerrilla Warfare” feel of the combat but the villain is really good and the setting is pretty solid too. I haven’t played 6 though. If I had to guess though it’s the same. More of the same.

4 is very similar to 3, in my opinion. It generally ranks lower than 3, but I'd attribute that to 3 defining expectations and 4 meeting expectations rather than pulling another groundbreaking move. 3 shared some notable elements with 2 but refined the direction of FC. 2 doesn't have magic and FC enjoyers begroaned 3's supernatural element, but here we are.

5 removed the supernatural element and got some mixed feelings. I'd put some of that on the fact that they brought the white American savior trope home to America. Instead of a foreign land under a whimsical authoritarian regime the West likes to go to war with, it's a religious cult in classic Americana rural towns. It's like changing from 1990s Batman movies to the Nolan trilogy. Gritty, more realistic, closer to historical fiction than fantasy. It harks back to the 1993 Waco Massacre.

I've played 6 on and off over the last few years. I read lots of hate but still enjoyed it. It's in Cuba, so it was back to being a far-off fantasy for me, with lots of story rooted in the 1960s revolution (though the game is present day). That is until the Gaza war flared up. Suddenly the game got uncomfortable for me. You play as a terrorist group fighting the military. That's not exactly different from 4. Sure, if you win, it's a revolution, but if you lose, historical speaking, the winners call it terrorism. I suppose the story could be considered weaker, but it's a change up. Instead of basing the story on you vs the big bad, it's rooted more in the friends you make along the way. You're building a revolution as one faction gathering 3 more.

There's also 3 half-games. Between the main titles, half of the prior maps for alternate experiments. I'd wait for all the titles to be discounted but would say the halfsies need to be discounted more. Granted, they're probably all regularly under $20 now anyway.

After 3 came Blood Dragon, using one of the islands for an over the top 1980s synthwave action comedy. It has corny 80s moves in lieu of superpowers. It's fun.

After 4 came Primal, a prehistoric version of the FC formula. I think it's neat that they developed a proto-proto-indo-european language for a 10,000BC setting. Spears, slings, clubs, and knives are the weapons here with some grenade-like items. There's spiritual elements resembling living a mythology. It's also fun.

After 5, New Dawn is actually a continuation of the story. A quasi-Fallout/Mad Max post-nuke-apocalypse world in which Joseph Seed still lives - and becomes an ally. I think it brought in supernatural powers from nuclear stuff. Probably my least favorite of the 3, but still enjoyable. It also introduced a number of the elements people begroaned in 6, so maybe that's why I don't mind 6 as much.

I'm surprised there hasn't been a halfsies between 6 and, presumably, an upcoming 7. 6 does have some extra story (dlc?) that has you relive parts of the prior titles. I haven't done them nor read about them much so I can experience them myself.

There was a similar mission in GTA San Andreas btw, I think they took inspiration from that. It wasn't nearly as cool as the FC3 one though

https://gta.fandom.com/wiki/Are_You_Going_to_San_Fierro%3F