Uh, oh, diffult (as always, when this question comes up every couple of years

).
No real ranking, just some remarks.
It was already mentioned, that MVs don't have the importance as promo tool they once had in the 80s and 90s. Has to do with the decline of MTV but more importantly with the decline of music industry as a whole since the 2000s.
So the budgets for MVs shrank accordingly and dramatically. You can say, that the vids since Medully don't really have high production value anymore (with the possible exception of the Huang directed vids for

and :album12: ). More importantly however, they feel more like "goodwill from the artist" than serious attempts for promotion. That doesn't mean they are meaningless, I think vids like 'Wanderlust' or 'Black Lake' are as personally important to her as any of the old ones (if not more so).
This all said, let's focus on the first four albums. I think every vid there is spot on in some way, it's just expressed so differently.
- Debut: every vid has a fresh feeling like the album itself, some stuff is cute (HB), some is maybe corny (Violently Happy), BTS is cool and avant-garde. It's telling, when the most polished vid (Play Dead) is also the most conventional.
- Post: every vid is different again, but even more vibrant and playful and innovative (like the album itself). The surrealist imagery Gondry invents for AoM and Isobel is just striking, in fact AoM has the most memorable "illogical dream logic" I've ever seen. Jonze's IOSQ but also 'I Miss You' both show Björk's love for playful sillyness and theatrics, Sednaoui's 'Possibly Maybe' is a remarkable exercise in thoughtful melancholia, which accompanies the song perfectly.
- Homogenic: the vids are proud and beautiful and theatrical (like the album itself). You can sense, there must have been bigger budgets for

than for any other album, they all have high production value. But the imagery is actually more reduced than before, focusing at times solely on Björk (Hunter, AIFOL, Alarm Call) or leaving her completely out (Joga). Only Bachelorette returns to the bigger scene, a smart and witty parody of the 'rags-to-riches' mythology which often accompanies pop stars (and perhaps a foreshadow of things to come?).
- Vespertine: The vids are beautiful, poignant and (partially) explicit (just like the album itself). They are even more stripped down (from a narrative point of view) than for Homogenic, but the intensity of e.g. Pagan Poetry feels nearly 'stingy' (well, it is, in some literal way).
The Vespertine vids were partially banned or heavily censored and not wildly seen. You can already see the effects of the reduced importance of MVs we talked about above, but not only from the airplay they got, but also from the reduced production. Some of it must have been deliberate, I think.
Cool addition: Jonze's 'It's in our hands' for GH.