I am talking to my friend in Oaxaca about this website and I want to say "Try it!"
would you choose pruébelo, trátelo o inténtelo
I think pruébelo would be most appropriate since you are suggesting that someone experiment with something to experience it, whereas tratar and intentar are more about making an endeavor or attempt at something.
Probar also has a sense of examining the quality of something.
I would say pruébelo because it has the meaning of testing or trying something out.
¡Haz la prueba!