an area that has really seemed to die is shareware games & adventure games, there were some really great games at one point and the companies, apogee, epic etc went on to become reaslly big but no new comanies seem to have taken their place . I know they wern't on a par with the graphics but I think the gameplay especially the platformer games would still have a major appeal if released today
some of my favourites ( not all shareware ) -
Countdown :wallbash: , took me ages to get to the end

Day of the tentacle
Sam n max
kings quest series
Keen
duke nukem
major stryker
bio menace
electro man
Thor, god of thunder (great little game
I still play some of these today when I wan't a quick game and would be only to willing to pay if similar games were being released today.
I won't pay above £35 for a game so the companies putting so much money into games are just loosing my cash as I ALWAYS wait until they come down in price. surely if something like day of the tentacle was released now it could be done for a much cheaper price and maybe some of the people who don't spend on games like myself might be willing to buy them