Here are my little stange and original tips for how to find ideas for games!

Let's start from that idea:
Idea 1#
Get outside and find an outdoor job!
Most of the people you will meet and most of the things that you'll do at job give exellent ideas for games start from pizza delivery to vegetable buissiness or to house cleaning or system administrating. All these can give idea for games that not yet has be found.

Idea 2#
In your Dreams!
Try to dream about ideas for games, take ideas from your dreams and found something interesting to create!
Find ways to dream about new ideas for games, I got some!

Idea 3#
Mix several types of existend games!
Ideas like doom with Pacman, Spaceships with Pokemon
Or excite bike with bomberman could bring very interesting results.

Idea 4#
Go out and look at things. Yeah. That's right. That's good for brain, and give ideas. Everything that goes outside might be a good idea for a game! Even if it's a plain, car crash!
Try also doing good deeds while going outside too because it's like playing a video game while doing this, good deeds refreshing your brain and give new energy!

Idea 5#
The holy books!
Try to read books about black magic, Bibalical or other religious books and legands, because it gives many ideas which many games are based on them (Even Pacman!)
If you start to adopt a religious book and belief you might find new ideas. Have you ever tried to ask God for an idea?

Anyway. These are my tips. Try to use them, It kicks! It helped me sometimes!