According to fans' reviews, The Office's funniest rivalry wasn't Jim vs. Dwight, but Pam vs. Ryan, and this was foreshadowed ...

While the host of a dinner party plays a huge role in whether it succeeds, guests have a big impact, too. For instance, attendees might make this faux pas.

Pam and Ryan never got one, especially after how he treated Jim after his promotion to corporate, but their animosity started ...