ET has your box office scoop!

'Iron Man' crushed the box office competition this weekend, scoring the best opening of 2008 with $100.8 million.

In the movie directed by JON FAVREAU ('Elf,' 'Zathura'), ROBERT DOWNEY, JR. plays Tony Stark, a billionaire industrialist and genius inventor whose captivity by insurgents motivates him to build a suit of armor to escape. Once free, he uncovers a nefarious plot with global implications and fine-tunes the high-tech suit to protect the world as Iron Man! GWYNETH PALTROW, TERRENCE HOWARD and JEFF BRIDGES co-star.

In second place was 'Made of Honor' with $15.5 million. In the romantic comedy, PATRICK DEMPSEY plays a serial dater who decides to settle down just as his best platonic friend (MICHELLE MONAGHAN) decides to tie the knot. Not content to let her slip away, Patrick accepts her invitation to be her "maid" of honor in order to win her heart.

TINA FEY and AMY POEHLER's 'Baby Mama' dropped to third with $10.3 million, while JUDD APATOW-produced 'Forgetting Sarah Marshall' dropped to fourth with $6.1 million. Stoner comedy 'Harold and Kumar Escape from Guantanamo Bay' (JOHN CHO, KAL PENN and NEIL PATRICK HARRIS) fell to fifth with $6 million.