Robin Thicke -- What I'm Really Thankful For ... My New Hot Girlfriend!

Robin Thicke is clearly thankful for one thing this holiday season ... his super hot new girlfriend.

Thicke was rolling through Malibu Friday with the top down ... showing off 19-year-old April Love Geary -- and the guy looked pretty damn care free.

Robin's had a tough year -- see here, here and here -- so he's gotta be stoked to be moving on.

Plus, April looks really hot naked. That always helps.