I have invented quite a few things over the years, but i dont really consider them inventions as anyone with a bit of engineering skill could have made something just as good if not better.
i have had some more revolutionary ideas too, but they always failed in a big way. i also have the habbit of inventing things that already exist, except my version is far more complicated/expensive or not needed. e.g. your television wall, you could just paint the wall white and use a projector. sure, it would not be as efficient, but would be 90% the same and cost about $50.000 less to make.
now days i dont concentrate so much on physical real world inventions. i try to come up with concepts that would work online or on computers. but lets face it, when competing with google and microsoft im a nothing.
my father is a stage magician, so some of my best inventions are probably solutions i came up with for his show, or new tricks that i came up with. i find im quite good at being told and illusion and then thinking of a way to pull it off.