Apocalypse easily THE WORST in the series.

Thank god, I was beginning to think I was the only one of the RE fans (games or movies) that thought that The Final Chapter was the WORST in the film series.

I agree with you for the most part on how I feel about each movie:

-The first one is probably the best in my opinion. I was introduced to the franchise when I saw my cousin playing RE 4 on the gamecube back when I was a kid. After that, he, my father, my brother, and I watched the first two movies back-to-back. This was before Extinction came out, so I was bummed that I had to wait almost 3 years for it. Like you said, the first one is not that bad on it's own, but in my case, the nostalgia factor saves it for me.
-Apocalypse, for similar reasons to the first one, has a special place in my heart, but also, as I've now played a lot more RE games since then, I feel like Apocalypse should be higher ranked among fans, as it's the closest and most faithful to the games. Is it 100% accurate? Hell no, but by adapting the Racoon City storyline as well as having a pretty good looking Nemesis, to this day I'm surprised at how much hate Apocalypse seems to get.
-Extinction was alright, I didn't like how it time-skipped without explaining in more detail what happened between movies, but the Mad Max vibe, Wesker finally making an apperance (though Shawn Roberts would do a much better job than Jason O'Mara), and seeing more jedi action from Alice was pretty neat.
-Afterlife is probably the second best in the series (possibly tying with Apocalypse) due to a fun and hammy Wesker, the soundtrack, the stylized fights scenes, and Chris Redfield fiinally showing up (he's only one of the main characters of the damn series after all). The trailers at this point would be known as falsely advertising how much Wesker would be involved, and how much the cliffhanger endings from the previous movie would effect the next one, but it was still entertaining overall (to be continued).

-Retribution...man, when I first saw this one, I REALLY didn't like it. Claire and Chris were gone, Wesker had even less screentime, Ada and Leon barely spent time together (hell, Leon was less emphasized than Chris, even though Leon shares equal main-character status in the games by now), and there was no story. The fifth movie felt more like a prelude to the final movie. But...after watching the movie again, I remembered it being better than the first time I watched it. Like you, I enjoyed the action scenes, which almost made up for the lack of an actual story.
-The Final Chapter....good God, this is the only one I don't like at all, even after re-watching all the movies again when I marathoned them only recently. This movie had no concept of continuity, the lower budget resulted in sloppy editing and worse graphics, and for a finale, it ended the franchise (which lasted a lot longer than one would expect) on a whimper. Paul Anderson didn't seem to care at this point, though I'm willing to blame Sony for possibly strong-arming Paul into choosing Sir Friendzone from Game of Thrones into having more screen time at the expense of the usually-entertaining Wesker. Not only that, but this one was BORING, not even fun in a campy sense.

I can't believe there are fans who are DEFENDING this movie, let alone saying it was any good or even better than other movies in the series, like are you f**king kidding me? I'll never understand that.
Before my recent marathon, I only liked 3, MAYBE 4 of the Resident Evil movies. Now? I like the first 5 movies, with the sixth one having no redeeming qualities, and I doubt that will change. The first 2 hold a special place for me due to nostalgia; the third was decent, not really all that good but not that bad either; the fourth and fifth had Wesker and other mainstay characters finally making appearances, along with enjoyable set-pieces to make up for the lack of a plot. The sixth....f**k the sixth.