So... this thread/discussion is simply meant to call out the physical differences and changes (and similarities) between the various versions of the Eva units and to give people a chance to say which they may prefer over another.
With that, here's some analysis via images. I've tried to stick to official art as much as possible for the clearest comparisons and have included a few figure images in addition.
So lets start with
Neon Genesis Evangelion
These will serve as the "baseline" for comparing all other iterations of the mecha as these were the "originals". Items of note with the original designs are the exaggerated proportions between the waist and the shoulders (though it does vary slightly at certain points and from picture-to-picture). The image below shows further exaggeration of the waist-to-shoulder ratio despite also being art (promotional in nature?...) from NGE.
Below is a screencap of Unit 02 which seems to continue the same proportions seen in the first image into the anime itself, where they stay pretty consistent throughout the series.
And as a figure example I offer up the Tamashi Spec XS-01R Evangelion Unit 01 figure. Admittedly, this figure does not convey nearly as exaggerated proportions as seen above, but that can be chocked up to the restrictions on action figure manufacturing and needing to ensure it has proper structure and posability at the *minor* cost of not being 100% accurate to the art for the series.
End of Evangelion
Unit 02 in EoE has the greatest screen time along with the MP Eva series.
Here we see that the exaggerated shoulder/waist ratio is practically eliminated, with the torso having been made thicker from the chest to the waist, getting rid of the previously skinny waistline and broad chest/shoulders.
The MP Eva series sticks to these same new proportions, though there are a couple shots in the film where they might look "skinnier" than normal, but that can be attributed to animation inconsistencies and the viewing angle of the particular shot.
Another small item of note is that in EoE, the Evas seems to lose the clear definition between their armor plates going from the chest to the waist along the sides of their bodies. This gives the armor a more "organic" look to it, though I personally think that's just the animation style they used in the film as opposed to a deliberate change to the design of the Evas overall.
Kotobukiya's Unit 02 EoE figure sticks to the new proportions rather well, translating them to action figure form.
Along with the the MP Eva from the same figure line.
Now we come to
Rebuild of Evangelion 1.0/1.1/1.11 You are (not) alone
In 1.0, we have a return to close to the original proportions of the Eva units seen in NGE. Broader shoulders, thinner waist, and we get some cool new color apps to boot. Unit 00 looks less like a traffic cone and more like an actual prototype testing unit and Unit 01 gains some green stripes and accents to offset the majority single-shade purple seen in NGE. But the main thing here is that the units look physically much more like NGE than EoE.
I couldn't find a definitive 1.0 concept piece for Unit 01, hence why it isn't pictured. That said, Unit 00 will be my primary go-to for 1.0/1.1/1.11.
The Tamashi Spec Unit 00 sticks very well to the proportions seen in the movie.
Bandai's model of the 1.0 Unit 00 has slightly more exaggerated shoulder proportions but that's more due to the type of shoulder joint used in the model than to a deliberate change made to the overall proportions of the model.
So now it's onward to
Rebuild of Evangelion 2.0/2.2/2.22 You can (not) advance
Here, the Eva units take on a more EoE appearance to their proportions with slightly narrowed chest and thicker waists, making their torsos appear more "blocky".
The only exception to this change in proportions is Eva Mark 06, which has an altered torso and arms designed to maker it look taller and thinner.
The Mark 06 actually has an additional plate of armor on the torso, which would lend to making the Mark 06 taller than the other Evas such as Units 00, 01, and 02.
Then the latest entry
Rebuild of Evangelion 3.0/3.3/3.33 You can (not) redo
3.0/3.3/3.33 is unique in the fact that we see TWO stylings of armor and proportions on the Evas in one film. In the first example, Unit 02β and Mark (Unit) 08α maintain the armor shape and proportions carried over from 2.0/2.2/2.22. Then, after their initial appearance, we are introduced to Unit 02γ and Mark (Unit) 08β and we see new armor that furthers the "blocky" torso look of the units in addition to completely changing the exterior armor appearance of the units themselves.
We are also introduced to the Eva Mark 09.
The Mark (Unit) 09 is clearly a successor to Unit 00 and has an armor appearance that looks much more like Unit 00's in 2.0/2.2/2.22 but has portions in common with the new designs from 3.0/3.3/3.33, namely along the unit's back and shoulders.
Finally, we have Eva (Unit) 13
Eva (Unit) 13 seems to combine design elements from both Unit 01 (head, waist, arms) and the new armor layout of Unit 02γ and Mark (Unit) 08β (legs, shoulders, back). The "taller" chest and addition of another set of arms adds to Eva (Unit) 13's height, making it the tallest Eva unit we've seen thus far along with giving it its own bit of flair and uniqueness.
So how exactly is this different from the older "Eva Anatomy" thread that was posted here? Well this is more specifically designed to deal with the changes we see in outward designs and proportions in the Evas themselves as opposed to dealing with anatomical items such as skin color, fingernails (y/n) and other related items.
Also, which set of proportions or armor appearance do you prefer on the Evas? Are you an NGE purist? Do you like the blended torso armor of EoE? Do you like the newest set of armor seen in 3.0/3.3/3.33? Feel free to tell us and say why.
Just remember that everyone is entitled to like whichever one they prefer for their own reasons. This isn't intended to create an argument about "which Eva is the best."