friendliest
friend-li-est
adjective
The superlative form of 'friendly', meaning most amiable, kind, and pleasant.
"She gave the friendliest smile to everyone."
Thesaurus
Synonyms: amicable, friendly, well disposed, well-disposed, informal, cosy, neighborly, intimate, hail-fellow-well-met, couthy, pally, matey
Antonyms: hostile, unfriendly