First of all - the more unique the content is the higher the hub's score will always be. If you write about something that people all over the web are writing about . . .it's going to be really hard for you to create a hub on that topic with a high score.
But let's say you decide to write about something that is obscure - like the differences between the turkey vulture and the black vulture, and how those birds are different than European vultures. . . .just an example of one that I've done that ranked pretty high. Not a lot of folks writing about weird things like that - you can't write about "lady ga ga" and expect to have a high ranking hub. . . .unless your ga ga article is just the best one ever created
My advice is to always write about the things that you know the most about - and let your personal expertise shine through. Do not be a trend chaser - those folks are a dime a dozen.