I recently marathoned Banjo-Kazooie, Diddy Kong Racing, Conker's Pocket Tales, Donkey Kong 64, Banjo-Tooie, Conker's Bad Fur Day, and Banjo-Kazooie: Grunty's Revenge. I had 100%ed Banjo 1, DKR, and both Conker games before, but it had been many years. And I played DK64 and Banjo-Tooie a lot when they were new, but never had the patience to beat them. They're all good games, but honestly they do become a bit of a slog.
>Banjo 1
Annoying due to needing to get all the Notes in one go, which was clearly a technical limitation of how they programmed the game, since all later games (and the Xbox versions of Banjo) didn't have this quirk.
>DK64
Like everyone says, it does have an annoying number of collectables, but I don't think it's as bad as everyone says. I do think the water level goes a bit too far with it though.
>Banjo-Tooie
Fewer collectables and is a shorter game but I still found it slightly annoying in some sections. I think DK64 and Tooie would both have benefit from more smaller levels, perhaps. I think the issue is that you spend too much time in each level. In Tooie it's only like half as bad, but it's still an issue. Give me twice as many levels that are each half as long. But I guess the point of this sort of game is that you only build one level and then just dump a thousand collectables in it so players spend forever with the level you made. Oh yeah, the shooting controls also bugged me. I hate that C-buttons strafe instead of aim, and aiming is vertically inverted, and you can't change either of these things, as far as I know. These people made Goldeneye years earlier, so you'd think they'd give you a few options in these regards.
>Conker's Pocket Tales
A simple little Game Boy Color game that deserves more credit. It's a fun adventure that honestly does evoke the more famous N64 game a little bit as far as gameplay goes. Both of them aren't collectathons, but adventure games. This one is maybe a bit too simple, but for a Game Boy Color game it's pretty good. Also at one point I switched the emulator to Game Boy (not Color) mode and it had way bigger changes than just color being turned off. Many sprites were very different, and I think I even noticed slight differences in level design. But I switched back to Color mode because I figure that's how it's meant to be played. But I should go back and play the non-Color version some time just to check it out.
>Conker's Bad Fur Day
An absolute technical marvel that blew me away when it came out. Sure, voice acting wasn't impressive by 2001, but it was on the N64. Even though I mostly played PlayStation, I was still impressed that they pulled it off on that hardware. And yeah the humor was a big draw. And I know, both of these things are passe and even frowned upon in some circles now, but I am playng these games to go back to the past, and I appreciate what the game did in 2001. However, I do find that by removing practically all the collectables, you're left with a game that is really just going from setpiece to setpiece. There are light puzzles, but I wouldn't say they're very fulfilling. The combat isn't exactly stellar. Also the shooting controls still suck. When the spectacle wears off, the gameplay isn't the greatest. I still definitely had a fun time overall though.
>Grunty's Revenge
Very underrated game. Too easy and too short, but honestly I like the level lengths here. Each level makes an impression but doesn't overstay its welcome. The issue is just that there's too few of them. But I suppose it's a GBA game so it's almost expected. That said, the Spyro GBA games are very comparable, and much longer. Spyro 2 and 3 on GBA might be of comparable quality, as well (they're pretty good, but the first one has some problems). Anyway, Grunty's Revenge does a great job at feeling like a legitimate Banjo game. The isometric view does lead to a couple of bullshit jumps here and there, but overall it works very well. It deserves to be remembered as part of the series more often.
>Diddy Kong Racing
It's a different genre but my autism made me include it anyway. I think it's a big improvement over Mario Kart 64, but Crash Team Racing improved upon DKR much further. Compared to that, the driving is too simplistic. That said, the hub world is a lot of fun to explore, and the hovercrafts and flying do add a lot of fun variety. Later kart racers improved it further, but those vehicles and the hubworld add enough to keep this game novel even in the face of later gameplay improvements.
Now I have to play Banjo Pilot, and then I'll probably go back and play Star Fox Adventures. But I've never actually managed to beat Star Fox or Star Fox 64 on the hardest paths, and my autism won't let me just skip them. I found it easier to skip Adventures, even though really from what I can tell it should be in my Rare marathon. I'll get to it eventually.