I see this question come up a lot, but I'm still having difficulty summing up what good content actually is.
I guess the best explanation is content that derives from your own knowledge and experiences which sparks a curiosity in other readers. That's why I always recommend that hubbers write about the things that excite them the most (expect for porn that's a no-no) and then that excitement (hopefully) is translated to the readers.
Do you like rebuilding cars? Write about that
Do you know how to paint? Write about that
You could even write about your favorite sports team - or writing itself.
We all have dopplegangers in life, and some of us have many - as such, what interest you will also interest others.
So, in essence, good content is anything you can share that will be of interest to others ... and if you aren't certain of what might interest others, investigate your hobbies, your interests, and things you have learned about over the years.
I hope this information helps. :)