Learn Italian: I clienti vogliono il risultato migliore. - The customers want the best result.

In Italian, you often use the same word for "better" and "best". To say "the best" (which grammar books call a relative superlative), you simply use a definite article (il, la, etc.) along with the comparative adjective. Because we have the article in il risultato, migliore translates to "the best" instead of just "better".

Could I change the word order and say il migliore risultato?

Yes, you can! Migliore is an adjective that can go either before or after the noun it describes. Both il migliore risultato and il risultato migliore are perfectly natural and mean exactly the same thing.

What if the customers wanted multiple "best results"? How does migliore become plural?

Adjectives that end in -e in the singular (like migliore) always change to -i in the plural, regardless of whether the noun is masculine or feminine. So, if you were talking about "the best results", you would say i risultati migliori.

I sometimes mix up the forms of "to want". Is vogliono a regular verb?

No, vogliono comes from the highly irregular verb volere (to want). The "they" form, vogliono, can be tricky to remember because it adds a -g- sound that isn't present in the infinitive.