Depends on who's buying. If it's not me then, sure! I'll tag along
Watching movies in theaters isn't a social experience anyway. And if it is then someone needs to be kicked out.
At home, however, I prefer to watch movies on my own if I'm going to really get into it. A movie can feel more personal when I'm watching it alone. And I don't have to worry about when's a good time to pause, bickering over the ideal volume level, and someone asking me stupid questions about stuff they'd know if they were paying attention or that nobody knows because the movie hasn't explained it yet.
Then there are the live riff-track jerks (which is usually me) who think their sardonic commentary enriches the experience.