...but not make a single penny from it, or invent a new flavour of bubble gum which makes you a millionaire?

Limitless green energy or popular new bubble gum flavour?
And just to clarify, I'm not saying there's anything wrong with bubble gum.  I used to really like bubble gum when I was younger.  The reason I chose 'inventing a new flavour of bubble gum' as the second option was because obviously compared to inventing a limitless green energy supply, bubble gum wouldn't really have quite as much benefit for mankind.

So which option would you go for?  Who would you rather be?  The rich bubble gum inventor, or the financially unrewarded inventor of a futuristic limitless green energy supply which has massive benefits for mankind?