In my case, it certainly would.
I'm already content to an extent. What I struggle with is lack of spare time. Having money would enable me to work less hours or give up work entirely and concentrate on what actually is important to me. Knowing my kids will be able to goto University if they want and to come away without debt, that would make a huge difference too.
It depends on the circumstances in which you have the money. i.e if you run a successful company and have to work 70 hour weeks, it wouldn't make me any happier. Lotto win, then certainly.