Utopia is one of those places where you can never really go wrong! Their menu selection is pretty extensive, with options for vegetarians and meat eaters alike, like some others have mentioned. You won't just get your average burger or burrito here, gourmet toppings and unconventional fillings make these meals well worth the already inexpensive price.
And yes, it's usually packed, and yes you will usually have to wait, but I'd say that's a mark of a good restaurant. It's gotta be worth it if everyone wants in, right? Their patio area is a bonus in the warmer months, and it's the perfect place to spend a few hours devouring a delicious meal and drinks.