Nearly five years after its launch, Blu-ray has reached the mainstream milestone.

More than 28.5 million Blu-ray players are now in U.S. homes, according to the Digital Entertainment Group, with 11.3 million of the players sold in 2010, up 62%. The holiday shopping season moved six million of the devices alone.

Having the hardware in homes significantly boosted the sales of Blu-ray movies last year by 68%, as well, according to the nonprofit org.

Fox’s “Avatar” ended the year as the top-selling Blu-ray title, moving more than 15.3 million units worldwide (five million were sold in North America). Pic also set a benchmark as Blu-ray’s overall bestseller.

Blu-ray also represented more than 30% of the disc sales for Universal’s “Despicable Me,” Lionsgate’s “The Expendables,” Paramount’s “Iron Man 2,” Sony’s “Salt,” Warner Bros.’ “The Town” and “A Christmas Carol” from Disney.

Although the DEG does not provide sales figures for Blu-ray titles, it noted that DreamWorks Animation’s “How to Train Your Dragon” and Disney “Toy Story 3” were also top sellers in the family category, representing “”further indication that the format is mainstream and, like DVD 10 years ago, significant growth will come from the family audience,” the DEG said.

So too will the sale of older catalog titles, which were up 52% last year. In the past, most consumers focused on picking up new titles but are now showing signs of investing in building a larger Blu-ray library.

In November, studios announced they would start rolling out Blu-ray 3D, and the DEG estimates that 100 Blu-ray 3D titles will be at retail by the end of 2011.

Overall, the DEG valued U.S. home entertainment spending at $18.8 billion for 2010, which was down 3.3% from 2009 – and hit its lowest point since 2001.

A decrease in DVD sales and rentals is mostly to blame. The DEG estimates that there are now 90 million households with at least one DVD player; 70% own more than one DVD player.

Breaking down last year’s numbers:

• DVD sales generated $14 billion in 2010, down from last year’s $15.8 billion.

• Blu-ray sales earned $1.8 billion; 170 million Blu-rays shipped to retailers.

• VOD brought in $1.8 billion, up 20.8%.

• Electronic sell through sales grew 15.7% to generate $683 million.

The sales figures were mostly in line with a report released by Screen Digest earlier this week.

“We continued to see strong growth in Blu-ray and significant gains in digital distribution this year, despite a tough economy,” said Ron Sanders, president of the DEG and prexy of Warner Home Video. “We also saw a slight increase in consumer transactions, which is a clear indication that consumer demand for home entertainment remains healthy.”