Mario Kart 64.

I never had a N64 myself and it's the only N64 game i played with a friend and later on switch. (Since then, i touched SM64 and OOT). To me, it aged well, unlike OOT and SM64 (which got remakes on ds and 3ds, ports on gc (OOT) and switch (both, through switch online only for OOT).

I know I have Mario Kart 64 behind Ocarina of Time and Mario 64 in the Top 50 thread, but it’s probably Star Fox 64. It’s one of the most replayable games there ever was and is timeless, constant fun.

I would say it's either Mario Kart 64 or Lylat Wars.
It did have RE2 and Starcraft ports and Shadows of the Empire as the lead platform, but I don't think that many played the games in the end. N64 had a handful or two of gems everyone should try out, but outside of them there wasn't that many good games.

Ocarina of Time and like most Zelda games are overrated,

Mario 64 was a killer product
Pokemon Stadium 1/2 are ahead of their time and the graphics still holds up
Original Smash Bros was legit as fck
Mario Kart 64 forever memorable!

N64 had so many absolutely wonderful, quality games that it's hard to choose one aside from SM64 or OoT/MM. But, since it has so many ones unparalelled on its genres, I'll try one per genre:

- Plataforming: Letting Super Mario 64 aside, Banjo Kazooie has to be the one. Its sequel, Banjo Tooir and DK64 were also good, but not that level of good.
- Racing: It's either Mario Kart 64, wich was a huge step forward from Super Mario Kart, but has been surpassed by other Mario Karts, or F-Zero X, the peak of its franchise with the incredible speed, awesome circuit design and unparalelled power metal OST. Wave Race also stands out with its ashtounding wave/physics desing and graphics. I really couldn't decide on which one is better. Also, there are other very good racing games on N64, such as 1080 Snowboarding, Cruisin' Series, Beetle Racing Adventure or Ridge Racer 64, but none of them are as good/important as the first three I mentioned.
- First Person Shooter: Goldeneye stands out as the pioneer, and Turok 1 and 2, being the 2nd the better, were also revolutionary. But Perfect Dark is the better one gameplay and multiplayer wise.
- Third Person Shooter: Jet Force Gemini by Rare is absolutely awesome story, gameplay and OST wise. Its controls could be refined, but the universe, planets, concept, varied gameplay, different protagonist with different skills to open new paths, setting, etc. were incredible. A masterpiece of science fiction.
- Shoot 'em up: It has to be Lylat Wars/Starfox 64. The best in the series and, for me, only matched on its genre by Rogue Squadron in the Gamecube. Awesome gameplay and level design, several routes full of surprises, varied and super-fun gameplay...- Fighting: Super Smash Bros. Period. Pioneer, extremely fun and deep gameplay, genre-changing... The first game in which I invested more than 200 hours.
- Adventure/RPG: The Legend of Zelda: Majora's Mask is way superior to Ocarina in almost every aspect, and way deeper in terms of story, lore, quests, gameplay, challenge... For me, it's probably the best of the system, although not as impactfull in the industry as SM64 or Ocarina, of course. Paper Mario was also an extremely good RPG.
- Others: Don't know where to classify it, but Conker Bad Fur Day was another masterpiece by Rare.

So... Any of the ones I mentioned as "TOP" in their respective genres could be considered the best of the system aside from SM64/Ocarina. It all depends on tastes, since all of them were genre/franchise defining on its time.

Sin N Punishment was the best game in its genre until its sequel. It may not have been as popular as Mario 64, but like Mario 64 of its time, it peaked the genre. Not to mention, they somehow squeezed a lot of VA into the game. SEGA invented the genre, and a Nintendo IP (though developed by Treasure) topped it.

Ok the term Shoot em up is reserved for another genre. Raiden, Ikaruga. Thunder Force. Gradius. Darius. R-Type etc etc that is the shoot em up genre. Goldeneye and Turok are FPS games.

Donkey Kong 64. Great platformer with lots of variety.

Pokémon Snap.
The idea for this game was unique. I was a bit disappointed that the game was on rails at first, I thought one would go around freely in an enclosed environment like a park for a few minutes and take photos that way. Even if I initially was not fond of the game i had spent some money on it and still played it, and the game grow on me. It is my most played game in hours spent on the N64. Hunting for higher scores might be seen as the lowest form of goal in games, but I really like it in this concept.

Banjo Kazooie - fantastic 3D platformer that's almost as good as Super Mario 64.

Shout out to Space Station Silicon Valley as a fun, quirky platformer, and Beetle Adventure Racing as a slightly overlooked racer.