This is the 50th most frequent Slovenian word.
vseh
"Vseh" means "of all" or "all" in English.
Here, the word "vseh" is used as the genitive plural form deriving from the root word "vsi" (all/everyone), used to denote comparison among multiple entities, specifying 'of all'.
Na pikniku so bili vsi zadovoljni z okusom hrane, najeli so najboljšega kuharja od vseh.
At the picnic, everyone was satisfied with the taste of the food; they hired the best chef of all.
The word "vseh" used here again as the genitive plural form is essential in stating 'out of all', indicating a superlative comparison among cities.
Obiskali smo najlepše mesto od vseh, kar smo jih videli.
We visited the most beautiful city of all that we have seen.
In this instance, "vseh" performs the function of emphasizing that among multiple stories, one is regarded as the most notable.