The best companion in Fallout 4 sure does clean up nicely. Introducing Generation 3 Nick Valentine, a mod that tweaks the hard-boiled detective's look to make him appear a bit more human-like. While I do think a big part of Nick's character and charm is in his wear and tear, it's fascinating to look at a sort of "what could have been".
Some more pictures:
Heck, if the synth eyes aren't to your liking, Nick can just run around like this: