The Avenida Álvaro Obregón could rightly be considered the "main street" for the Roma Norte neighborhood. Running west to east from the Parque España it ends only at the Jardín Pushkin and Avenida Cuauhtémoc.
The reputation, "hipster," is not un-earned. Weekends, the park running down the middle of the avenue is lined with vendors and there is always expresso and cake.
The Avenida Álvaro Obregón runs through much of Roma's art gallery territory, too. It's one of the best-known commercial thoroughfares in the area. It's also a great street for dining, a night out, or for simply a stroll.