Can adaptations live up to the book?

I'm sure I'm not alone with this, but where I read I get a clear picture when I read a book, so when a movie comes out I've already got some idea of what it should be like. I do try to see the adaptation with different eyes because I know that it's being shown on a different medium and some things written in words cannot be shown on the screen.

There have been some that I loved, but I admit I haven't read the books yet. I just saw Red Riding Hood and thought that was done very well, so I'll have to go out and get the book to see whether the movie still lives up to the book.

What can they do to adaptations to change them from the books (this can be for the good or for the bad... mostly the bad)?

1. "Watered down" the action
   I have seen this happen. The content in the book is deemed too violent for the audience so they either eliminate it or change it so that the "children" will be able to watch it... even though they are the ones reading it.
2. Change the endingWhen a book ends one way I expect the movie to also end that way, but there are some movies that just change the ending so that it's not as "sad".
3. Cutting crucial subplotsI know movies have to tell the story of the book within 1.5-2 hours, but sometimes the subplots that they cut I feel are crucial to the story or, when cut, will change the motivations/sympathies of the main character.
4.  Cutting charactersOkay, once again I know that they have to tell the story within a certain time frame, but sometimes the characters that they cut are the characters that add a bit more interest/humour to the story. Or I just love them and can't believe they've been cut.

So, do you like adaptations or just prefer to stick with the books. Have you seen any that lives up to the book? And, what don't you like to be seen in the adaptation?