Most applications need some kind of control grouping because they'd look cluttered otherwise.
GroupBox is a good thing because the user is used to it. But likely the user will recognize other grouping mechanisms as well. I like the Krypton Toolkit with its HeaderGroup approach to grouping, because it allows to display more group-related information in the top and bottom header. But if you don't need that, a traditional group box should be fine. On a dialog box, that is. On main windows, it doesn't fit in my oppinion, in contrast to the mentioned HeaderGroup, which easily fits both scenarios.