Flavor additives to Cider?

Last year I had an endless supply of apples so I decided to make hard cider. I swung for the fence with 10 gallons of cider pitched with champagne yeast and 5 gallons pitched with ale yeast. Now the cider sits in carboys and is clearing up nicely, the only downside is the taste isn't that great. The taste of hooch is very apparent and I was wondering if I could add a campden tablet to kill off any yeast left and add some flavors. My other concern is what type of flavors or spices should be added to my cider.

I would suggest that if you add flavors to pull off 1 gallon batches and flavor those. I'd hate to see you add flavors to something that will probably be the most awesome cider you've every tasted in a few months.