toothpaste. It's less about what you use and more about how you use it. Get rid of all the plaque, however you do it, floss, use fluoridated toothpaste and get regular check-ups.

I use this, and I like it:
http://www.target.com/p/oral-b-professional-care-rechargeable-toothbrush-with-bonus-deep-sweep-brush-refill/-/A-15296609

I just had a rep in my office trying to talk up a new toothbrush that syncs with your cell phone and shows how hard you brush, how long you spend in each area, how frequently you brush and some other useless stats. It made beeps if you were brushing too hard, and dings every 30 seconds to switch areas. Jut get the plaque off.