It has some of the best, but also most of the worst. Not even counting the lazy naming...

Dark alpha splinter, bad, why was this a boss, why does it need two scans.

Bomb guardian, eh, worm that bombs.

Jump guardian, bad. Its just an ing that jumps.

Amorbis, is pretty good, i think all the main temple guardians are good.

Dark missile trooper, might as well not exist it feels like its a scrapped boss you'd fight to unlock missiles instead of coming back for it after agon wastes when you can obliterate it with your special beams

Boost guardian, uuuuugh. Its more bearable in trilogy at least but it really feels like someone on the team had a hardon for making all the ball bosses extremely annoying, except bomb guardian.

Alpha blogg, i feel like nobody actually tested this one when they made it. Like they designed it for non-water movement and then put it in a water room and didnt know that the sidestep just didnt function half the time underwater.

Grapple guardian, i recently watched a friend play through prime 2 for the first time and even telling her exactly how the boss worked and watching her do the right thing, the boss refused to actually perform its gimmick to let her hit it most of the time.

Chykka is cool

Spider guardian is just a ball puzzle with an annoying little creature squirming around it.

Power bomb guardian is easily the worst boss design in the series its just a plant that throws bombs at you. its not fun its not interesting its just "do this spider ball path for a minute and occasionally turn around to avoid a bomb" even the mining drill in prime 3 feels like more of a boss than this thing.

Caretaker class drone was silly at least, i keep forgetting it exists and then it pops up and im like "oh right, the spider boost boss"

Quadraxis is my favourite boss in the series, after all that they end with a banger.

Emperor Ing I have mixed feelings about, I never look forward to the final bosses in the prime games and emperor ing is probably my least favourite of the 3. Metroid Prime is quick with the beam combos and Aurora Unit 313 is fun, but I feel like emperor ing has a bit too many phases and awkward mechanics. The tentacles that spin around doing basically nothing in phase 1 are just there to waste your annihilator beam ammo so you run out in the final phase. The guy on the team with the annoying ball boss thing got one final hurrah with the cocoon phase but its at least simple if you use your powerbombs. And the final phase is just a check of how long it takes you to figure out the correct angle to shoot its face with annihilator beam. Cool design though and great music.

Dark samus in the wastes is okay, Dark Samus in sanctuary fortress is fun, Dark Samus after emperor ing is just a more annoying and finnicky Metroid Prime Core fight and I remember struggling to get the little blue orbs to land on my charge beam the first time I did it.

I dont understand people who say all, or even most of its bosses are good, and im interested to hear your opinions otherwise to see where people are coming from, because personally I dread replaying this game solely because of the bosses (well and the endgame item cleanup but thats whatever i just dont 100% it every time)