Funny you should ask this question...I just finished reading a book that I felt had way too much dialogue. I won't name the book but I've never ended a book with that thought...until now. To answer your question, I'd rather read a book with narration as too much dialogue can be boring.
definitely narration for me. Especially internal monologue-style narration.That's why I love DeLillo. I can't stand dialogue. If I'm interested in dialogue I read plays, I love Sam Shepard's plays. I agree with the earlier comment that narration is easier to write - dialogue is easy to do badly. That's just my view though, I'm not a creative writer.