TOP TEN TECHNIQUE
Think of a very broad topic such as video games, music album's, music software, laptops, films etc etc, it's limitless really. Then go into google and type "top ten 'insert your broad category here'". This will give you the top ten things in a certain category that everybody is searching for. Pick something that interests you and ONLY THEN look into researching that keyword in a keyword tool such a google, market samurai or Longtail Pro.
This might sound really simple but you'll be surprised as to the niches you can find that you would have never even considered. Also there are not many people using this technique as most SEO's or Marketers go straight to the keyword tool. Hope this helps you out a bit buddy.