You got the top 8 right, I think (except one could add Xbox One S, which is actually marginally stronger than the base Xbox One).
When it comes to Wii U, PS3 and Xbox 360, I would say they rank:
Xbox 360
Wii U
PS3
Despite all the hype around the cell processor, the Xbox 360 outperformed the PS3 in almost every single multiplatform release, even in late releases, such as MGS V. I know people like to point to PS3 exclusives to demonstrate how it was more powerful, but I think that is a completely hypothetical arguments, as those games weren't on the 360. It is also not obvious to me that the best looking games that generation were PS3 exclusives.
The Wii U is a bit more tricky, as it does have some improvements over X360 and PS3, but the processor is probably worse than the 7th gen consoles, multiplats were mostly worse than at least the X360 versions, while somewhat on par with the PS3. More optimized ports like Bayonetta were probably best on the Wii U though. I would guess Wii U is pretty much tied with X360, with PS3 worse than both. The Switch is clearly stonger than all three though given the ports it got.
While the order of the 6th gen is obvious: Xbox > Gamecube > PS2 > Dreamcast, where the Wii, 3DS and Vita and PSP fit in is less trivial. My best guess is that the PSP is still weaker than the Dreamcast, but stronger than 5th gen consoles. The Wii is essentially an overclocked Gamecube, which would still put it below the Xbox (I have also seen more impressive things on the Xbox compared to Wii), 3DS is probably between Gamecube and PS2 and Vita is stronger than the Xbox.
So:
Vita
Xbox
Wii
Gamecube
3DS
PS2
Dreamcast
PSP
DS, PS1, N64 and Saturn are the most difficult to rank. N64 is probably stronger on paper, but the shortcomings it had because of the cartridge size meant the textures are lower resolution compared to the others. DS games look like shit, but the screen quality is part of the reason. I think Super Mario 64 looks better on N64, but Mario Kart DS looks better than Mario Kart 64. The Saturn and PS1 have better textures and performance than most N64 games, and I actually prefer how they look. Comparing multiplats, the Saturn usually did better than PS1 in 2D games, but the PS1 usually had better looking 3D games. However, I am still not sure if PS1 was actually better at 3D. Saturn used quads as polygons instead of triangles, which made character models look a bit rough, but it did have less of a texture warping issue and the extra processor allowed for infinite 2D plains which was a decent compensation when draw distance would otherwise be a problem. N64 certainly had better looking polygon models than the competition though. So all in all, this is probably how they should be ranked:
N64
DS
Saturn
PS1
The rest of your list seems correct, except the SNES is stronger than Genesis.
