Showmars is one of the few places I feel like I could honestly say I've had the entire menu. It's a local staple, so I've been going to various locations my entire life, sampling all that they have to offer. They've pretty much got fast casual down to a science, and I've never been disappointed.
A few of my personal faves are the Grilled Chicken pita, the Old Fashioned Pita Burger, and the seafood, which is better than a lot of places that specialize in seafood only.
But everything is good. If you've never been, just look at the menu, and pick a dish you typically enjoy. You'll love their take on it, no doubt.