Derme302, weird that, I only found that the other day. Kinda useless.. I mean, one idea was to race kitchen utensils ;p but keep clicking on it for new ideas can probably generate different things in your head, so it can be useful for that. I don't think I got any ideas from that that anyone could follow seriously ;p
Codeman320, ideas come from many places. Movies, books, music, artworks, life in general.. and of course other games. Ideas can just pop into your head without you even looking for them when watching a movie or listening to music. Pick a game genre you like, or at least one that wouldn't surpass your skill level.
It really does make a difference if you can choose a game that you can finish. Start with smaller games. You like Mario? cool.. set it in an apocalyptic world, or in space, etc. Look at older games for ideas. Take Dizzy (old retro game) and add your own flavour to it. Just don't try and create the 2D version of WoW if you can't spend at least a year developing it. Think about your drawing skills too. I'm an artist, but rectangles do me for getting started with gameplay ideas. If it's fun with horrible looks boxes, then you're onto a winner But as an artist, I do find it hard not to jump into photoshop to make things look a bit prettier ;p
The main thing is... DO THE GAME YOU'D LOVE TO PLAY. Everything else will flow.
*excuse my incoherent rambling.. I'm a tad tipsy ahem