I've walked out of several shows (Always at intermission though). If my attention is not held at a show it just makes me cranky and claustraphobic. It's better for me to leave.
There was a production of Who's Afraid of Virginia Wolf at my college with a male in the role of the leading lady. Not that I particularily minded it, but it was a bit odd. I didn't think there was enough tension amoung the actors though, and the only reason I stayed for the second act of the show was a brilliant performance by the leading male.
A REALLY bad production of Cabaret. Now, it's not one of my favorite shows but I can enjoy it enough. Few of the actors were focused and it was being performed in a very small little cafe type thing we have. There was no room for the dancers to dance. I was embarassed for them.
A production of The Shape of Things. The acting wasn't great, but moreover, I just hated the show.
The only Broadway shows I've wanted to walk out on but couldn't because they were school trips were Bring in the Noise, Bring In The Funk (I was 11, and they were making fun of my idol Shirley Temple. How dare they! It was my second Broadway show and it was certainly not the R&H I grew up with. I didn't really get satire then), The Invention of Love (I was probably about 16...but I'm still not a huge Stoppard fan. This show bored me to tears. And The Sunshine Boys...I was fairly young...probably 13-14?
"This ocean runs more dark and deep than you may think you know...I'll be the fear of the fire at sea."
-Marie Christine