Happy Escapism vs Doom Gloom and Realism

Given a choice I would choose to read a book with a happy ending any day, reading fiction is for me an escape from a sometimes not very nice reality. Guess thats why I like LOTR,Narnia, that type of book.
If you were given a choice between reading a book that had a fairly positive outlook and a happy ending, or a book that was very gloomy and a sad end, which would you prefer?
I hate the type of book that is all about miserable gloomy people living lifes of poverty or suffering, falling in love with the wrongg person, struggling to escape their misery and always failing. When I read fiction I want to feel good, to feel happy, not depressed. How do rest of you feel?
Worst kind of book story is one that you read right through and then it doesn't even have an ending!!! That makes me so mad!