It was bound to happen. After 20 months since its official launch, Nintendo Wii is now the leader of the gaming consoles in the United States.

According to the latest figure released by The NPD Group, the company that tracks the gaming sales in US, Nintendo Wii has 11,008,200 units surpassing Microsoft’s Xbox 360, which stands 10,465,900 units.

Since the beginning of this year, Nintendo Wii has enjoyed strong sales month after month and June made no exception.

According to The NPD Group, Nintendo Wii was again the number one in June with 666,700 Wiis.

Not so surprisingly, PS3 had also a good month and the release of Metal Gear Solid 4 has boosted the sales. Sony sold 405,500 PS3s almost twice as many as Xbox 360.

Microsoft sold only 219,800 Xbox 360s and now has an installed base of 10,465,900 units.

Nintendo Wii’s success was predicted two monts ago, when Microsoft said its gaming console has moved over 10 million units milestone.

In the handheld market, Nintendo DS was again the champion with  783,000 units sold, while Sony’s PSP moved only 337,400 units.

In the software category the best selling game title of the month was Metal Gear Solid 4 with  774,600 units.

Earlier this week, both Microsoft and Sony announced price cuts for their gaming console. Microsoft’s Xbox 360 Pro console with 20 GB hard drive is now selling for $299, while Sony has announced a 80 GB PS3 for $399.