So far I've had good luck with this challenge--haven't had to give up on a book yet.
But I picked up Flavor of the Week by Tucker Shaw, and by page 51 knew I couldn't finish the book. It's hard to stomach a passive protagonist. This one let himself be walked all over by his best friend, thrust into friends-only territory by his oblivious crush, and pretty much shoves his own light under several bushel baskets. And of course by the end of the story, he would have fixed all this, but I just couldn't make myself get there.
I was really looking forward to it too. The cooking, the love story, the fact that a guy was cooking--but the passivity killed it. Sigh. I'll probably keep the book long enough to copy the recipes. Those looked killer.