This is the 659th most frequent Hungarian word.
legjobban
"Legjobban" means "the best" or "most" (superlative degree).
Here, 'legjobban' is used as an adverb, modifying the verb 'kedvelem' to express the highest degree of preference among a group.
A barátaim közül őt kedvelem legjobban.
Among my friends, I like them the most.
'Legjobban' serves as an adverb describing the verb 'éreztem,' indicating the superlative degree of feeling good in a specific context.
Ezen a tájon éreztem magam legjobban.
I felt the best in this region.
In this question, 'legjobban' intensifies the verb 'tetszik' to inquire about the painting that is liked to the highest degree.