It is a fact of urban regentrification that no neighborhood reaches its sociocultural peak until a new coffeehouse opens there. Which is why, despite all the lovingly maintained houses, despite the perennial popularity of Arcelia's and SqWires and despite the glorious park from which the nabe takes its name, Lafayette Square didn't arrive until this year, when Perc on the Park opened its doors. It is everything a neighborhood java stop needs to be: cozy, quiet, decorated with local artists' works and staffed by hipster intellectuals, a great place for catching up with a good book or a good friend, and liberal in its coffee creations. You can get your joe mixed with soy milk or sugar-free syrups, served iced or steaming hot and with a nice pastry or bagel on the side. (Try the crumbling brownie creation.) There's a scattering of outdoor seating, and during hot days a dish of water awaits dog-walking patrons. Lafayette Square, welcome home.