Concierge.com's insider take:
The most heavily visited of the Ionian Islands, Corfu draws sun-worshippers and resort-hoppers (and is a good jumping-off location for more islands), but it also attracts history and architecture buffs. Corfu Town retains the hodgepodge cultural elements brought over by the French, British, and especially the Venetians—all of whom ruled at different points over the past eight centuries. Venetian architecture abounds: Instead of the usual white sugar-cube-style buildings endemic to Greece, structures here tend to be ocher or dark pink, with shutters and red-tile roofs. The most venerable Venetian structures are the town's two fortresses: the Palaio Frourio, or "Old Fortress," originally a Byzantine structure that was renovated by the Venetians between the 13th and 15th centuries (30-266-104-8310), and the Neo Frourio, the "New Fortress," built by the Venetians between 1576 and 1589. Both are open daily to tourists for a small admission fee.
Two other sites that attract culture vultures (and buses of package tourists—unless you arrive early) are the palaces-turned-museums of Mon Repos and the Achilleon. Mon Repos, the closest to town, was once the summer house of the Greek Royal family; it has two Doric temples on its grounds, a beach, lovely gardens, and a theater (30-266-103-0680; closed Mon). Slightly farther afield in the village of Gastouri is the Achilleon, a rococo palace built in 1890 by a hypochondriac Austrian empress who settled on the island to take advantage of the clean air (30-266-105-6245; open daily). More recently, the property served as a backdrop for several scenes in the James Bond film For Your Eyes Only. Corfu Town has tons of restaurants and cafés, making it the easiest place to stay if you're only here for a bit. The waterfront is dominated by a grassy esplanade called the Spaniada, which includes a cricket ground and is ringed by the Liston—a gorgeous stone pedestrian walkway that's the best place to while away the afternoon with a glass of wine. For shopping, head to M. Theotok Square and the streets around the church of St. Spyridon.
Beaches! Yes, Corfu has dozens, but they're a pebbly bunch. The best are Glyfada, a sceney favorite of wealthy Greeks; Sidari, which has rock formations such as the hyped Canal D'Amour (where the cliffs form a canyon in the sea that you can swim through—very romantic); and rocky Paleokastritsa, overlooked by a cliff-top monastery whose museum contains what monks claim is the skeleton of a sea monster.