I was the one being forced, and I TOTALLY resisted.
My close friend and I were at her house waiting for a few others to join us. They were desperately late, so she pretty much said, "We're going to watch Buffy," sat me down on her bed, and turned on "Once More With Feeling" (and I actually just watched this one in the chronological order to much better results...).
I was not a fan. It may have been because she had already been comparing me to Anya, even then, and Xander, so she kept pointing them out. Or, because she had to explain every little thing. Anya sang her bit in "I've Got A Theory/Bunnies/What Can't We Do" and I'm looking at her like, what?
We ended up stopping right before "Dawn's Lament."
To her benefit she did her best, and later, she did get me into Angel (we watched maybe half the season in one night...). But I didn't get into Buffy for about six more months, and I did it on my own.
I have thought about forcing some people meself, though.