"Where I play a video game, and milk it for as many videos as possible"
I love your honesty, sir. Also I don't mind watching a lot of videos about Crash games.

Sadly I have yet to play this game

While i'm watching this video, I want to say that polar bear perfect relics are not that bad as everyone says :), completed them today

I... Honestly agree with your Top 5.

Also, N. Tropy's boss fight isn't the worst by any means; if we wanted to talk about bad boss fights, we could check some of the other Crash games, like the first Crash Bandicoot.
But still, nobody could expect much from the very first fight with Papu Papu.
N. Tropy, instead, is presented as the main villain for most of Crash 4, so what we got in the end just didn't live up to our expectations. This boss fight had no excuses for being so disappointing and not even involving the other playable characters (the thing that Crash Twinsanity did definitely better in the final boss battle).

In the end, I am glad N. Tropy wasn't the real final boss, because such an ending would have been incredibly disappointing.
The Doctors N. Tropy are so cool, they deserved much better than this.

What I liked: The top 3 you have are absolutely incredible.

But there are wasted opportunities. I don't think N.Gin is first boss material. Maybe a non-scientist like Tiny or an original mutant would be better? Also, Brio and Tropies could use some more phases.

Great video, Scummy Rebel!  My favorite bosses in this game are N. Gin, Louise (Jetboard Jetty), and N. Cortex (Past Unmasked).  I loved the idea behind the two N. Tropys, but their boss battle wasn’t as much as I was hoping it would be.  I’d love to see more of them in the series, along with Papu Papu, Nitrous Oxide, Pinstripe, Rilla Roo, Koala Kong, and one character who’s not a boss - Pasadena O’Possum.  There’s so many characters I’d like to see more fleshing out on, along with the original Tawna.
So Scummy Rebel, what retrospectives and level rankings do you have planned for next?  Hope that PlayStation Underground website I sent was pretty helpful - I’m excited for your retrospective on that series!  It’s a terrific series that was loads of fun, and I hope you enjoy it too. 😉👍
Thanks for another great ranking, Scummy Rebel ⭐️⭐️

Toys For Bob really wasted oppurtunities for the likes of Tiny, Papu Papu and Komodo Brothers among others for ths game. As far as I'm concerned, none of these bosses earn the top spot.