That sounds a bit like you're already demotived because you're setting the bar to high.
I found that I get a real kick out of recycling old, simple ideas that are doable just by myself and adding new ideas to them. The feeling of your code producing something on screen at the point where everything becomes playable and fun is really priceless, no matter how simple the game mechanics or the code behind it really is. That's the point where I usually get inspired with new ideas for improving an otherwise old concept.
Well, that was how my own humble game Hyper Blazer was born. I didn't have to worry about flashy graphics, beautifully animated 3D models, deep story lines, or any other things that tend to take millions to produce.
The feeling became even more priceless when that game turned out to be the 2nd most played game on my website (for more than 8 months now!), beating loads of classic emulated games like Ms. Pacman, After Burner 2 and Sonic the Hedgehog. I'm not saying my own game is better than any of those but for some reason, the visitors of my site play it much more. Priceless!
If you want to create your own game but you don't know what to go for, first think of a concept which you *can* do just by yourself. There are so many old but still viable ideas from the 70's, 80's and 90's to improve upon... And of course even more original ideas! Just as long as you don't start something which is simply impossible to do just by yourself.