I would say to leave the aspect ratio alone.
You hate the black bars? My suggestion would be to think good and hard about what your priorities are when it comes to viewing material on your TV.
Lets see if we can put this in perspective. Say you own a nice work of art. Lets say you also have a frame that you like. The problem is that the painting is too wide to fit in the frame. Would you trim off the sides of the painting or would you get a bigger frame? What if the picture is too small for the frame? You get a matte for the picture so that you can see the whole painting and it fits nicely into the frame.
These TV shows and movies are art. They may not be great works of art, but they are, nevertheless, art. The black bars on your screen (on the sides for 4:3 material or on the top and bottom for 2.35:1 material) are the mattes. Its that simple. They are the way that you can enjoy material that doesnt fit your screen.
If you focus on the black bars, youre missing the point. Dont watch the bars, watch the shows. Obviously its your choice, but you did ask for our opinions. I believe youll be much happier in the long run if you can change your point of view and learn to embrace the black bars for what they are: a way to enjoy different sized material on your fixed-size TV.