The fact that Johnny Mango has remained wildly popular without changing a thing on their menu in years means they must be doing something right.
One of my favorite things about Johnny Mango is that they cater to vegetarians and meat-eaters alike. I took my parents here while they were visiting because my step-mom, much to my carnivorous father's strong appeal, recently decided to try out the whole vegetarian thing. Normally my dad would stomp his feet at the idea of eating somewhere billed as having "good vegetarian options" but to his surprise, he thoroughly enjoyed it (he ordered the flank steak, of course). In fact, the last time they visited my dad even suggested going back!
Now for food suggestions: The Pad Thai is really yummy but everyone else at your table will order it so do yourself a favor and try the fried rice (this may be the most blank-looking-yet-full-flavor meal I've ever encountered). You also can't go wrong with a quesadilla alongside a fresh fruit margarita but go ahead and order a pitcher, you're going to want another, and then another. ;-)