I voted yes, but only if I'm stuck. I mean, sometimes I'll know the controls for a game because I got that information from Wikipedia, like Kirby Canvas Curse. Then it has a tutorial, so the manual is made useless anyway. And for games like New Super Mario Bros., does anyone NEED a manual? Run, jump, stuff. Again, there are other sources prior to release that talk about the stuff you can do, like ground pound and wall kick... so you're good to go.
And sometimes when I'm bored, I just go read manuals. For hours.