Play video content EXCLUSIVE

No one is more excited about the blockbuster Lakers deal than Dwight Howard -- who was sporting a megawatt smile on his way out of a Beverly Hills hotel moments ago ... telling TMZ, "I'm just happy."

Howard pulled out of the hotel in a gleaming white Bentley, and it was obvious the big man is pumped to play for the Lake Show.

We asked Howard why he finally decided on L.A. -- and he responded by saying it wasn't entirely his decision ... claiming, "It wasn't on me."