Funnest is a regular superlative of the adjective fun. However, the use of fun as an adjective is itself still often seen as informal or casual and to be avoided in formal writing, and this would apply equally to …
A well-argued case for funner and funnest being the logical and natural comparative and superlative forms for fun. Yet, I doubt I could ever bring myself to say one day, let alone write, “This …
Funnest class in your opinion and why? Mage can be really fun. Lots of potential to do high skill farming with pro strategy. Lots of community interaction with portals and food. I personally have …
I think fun as an adjective is quite common. Merriam-Webster has a definition for this. It does state that "funner" and "funnest" are sometimes used but I, too, prefer "more fun" and "most fun". …
Funnest Tank for M+ - General Discussion - World of Warcraft Forums