Personally think that the best ideas come out of solving problems for yourself or that you feel no one else can solve better. I also wouldn't be too worried about crowded and/or small markets, especially if there is an opportunity for the space to grow.
It seems a bit forced to look hard for an idea, its usually a process, not something you just come up with overnight. Not to be a downer but it might be better to look for some work until you find something you truly care about.