Game ideas

I'm thinking of what to do next. I want to make a game for PC that's for sure.

I have these ideas :

1) Space station manager - I have written about it previously.
2) Space trading/exploration game - you have one space ship and some cash, you may travel across universe, be a pirate or fight with ones
3) Something like Sigmore Mines but for PC..
4) A game where you flight an old aeroplanes (yes I've watched recently "Flyboys" ;) )
5) Platformer
6) other ideas?