A lo mejor is used to say maybe.
A lo mejor vamos a ver una obra de teatro esta noche.
Maybe we'll go to a play tonight.
Sí, a lo mejor.
Yes, maybe.
Remember how you can add the ending ‑ísimo to a word to say that something is really easy or really fun? Facilísimo, right?
That’s right! Just one more thing: the gender of nouns will help you choosing between ‑ísimo or ‑ísima endings.
Finally, use ‑ísimos or ‑ísimas when talking about more than one thing.