Freni e Frizioni occupies a former mechanic's garage on a small Trastevere piazza, kept the original signage, and built around it the most-imitated aperitivo bar in Rome. The buffet runs from 7pm to 10pm; the drinks are spritzes, Negronis, and a short list of house cocktails the bar quietly takes seriously. The crowd spills into the piazza, sits on the steps opposite, and treats the place as the city's communal living room. Twenty years on, it still does this better than any of the bars that copied it.
Go on a weeknight if you want a table. Go on a weekend if you want the noise. Either way, order a Negroni Sbagliato to start - the bar's version is the textbook for it - and then move on to whatever is on the seasonal card. The food at the buffet is genuinely good (cold pastas, regional cured meats, vegetable dishes the kitchen rotates daily), and is the smartest €12 you will spend on Trastevere drinks-and-snacks in a single evening.
No reservations. Arrive before 7.30pm on weeknights for a table, before 7pm on weekends or expect to stand. Cash and cards. The piazza fills with the bar's overflow on warm evenings - if the indoor room is full, take a Negroni outside and find a step. That is the move.
Nearby in Rome: Necci dal 1924.