The Sony PS3 outsold the Microsoft Xbox 360 in May in the United States according to new NPD video game sales numbers. In February the PS3 outsold the Xbox 360 the first time.

Sony sold 209,000 PS3 consoles and Microsoft sold 187,000 Xbox 360 consoles during last month.
Nintendo blew both away again with 675,000 Wii consoles sold.
GTA 4 was the bestselling game in May, but the projected surge in hardware sales for the Xbox 360 and Sony PS3 did not materialize.
It is expected that the PS3 will continue to do well in June because of the release of Metal Gear Solid 4.

The predicted surge in Wii consoles did happen. Nintendo apparently managed to put more Wii consoles on shelves along with the Wii fit launch.
Via Reuters.