Inventions useful and useless

I have been assigned the task of picking out a hearing aid for Mr Charm, courtesy of his doctor.  I've been researching these gizmos, asking people with hearing aids what kind they like best, and nobody has a good word for any of them.  My late father owned several of them and left them all in the drawer.  Apparently the technology is unsatisfactory and they are disliked by users and non-users alike.  Only cable providers are more unpopular.

So I got to thinking about gadgets--which are satisfactory, and which need more work?

Here's my list.  You might have one of your own.

Great inventions:  Flat screen tvs, dishwashers, air conditioning. microwaves, eyeglasses, and above all iPhones all do what they are expected to do and then some. 

Need more work:  garbage disposals, digital thermostats, electric cooktops, hearing aids, Bluetooth devices, and above all, pantyhose.