I will give a book a solid chance sometimes if it's a lot of set up I'll read half but if it's not moving the story forward, or appealing to me in some way I won't finish it. Now I think alot of what makes one like a book is just your individual tastes. Is it a character you personally can relate to etc.
The really brillant books are the ones everybody likes! Oh and no reading the end first.:( I don't even like when you read an excerpt for an umcoming book and they don't start that with page one.