Right by the Trevi Fountain, L'Antico Forno is a fast, budget-friendly bakery where you should grab a pizza al taglio slice, focaccia or a fresh pastry to eat on the nearby steps. Service is quick even when there is a line, seating is minimal so plan to take your food away, and they typically open early and stay busy through the afternoon. Bring small change just in case, though cards are usually accepted, and pick a hot slice plus a coffee for an easy, authentic Roman snack.