Whether you have a cone style drip brewer or a basket style drip brewer you will need to use a filter to hold the coffee grinds and prevent them from getting into your coffee pot (and generally making a mess of things).
Most people think of a white paper filter as the only option. If you are going to use a paper filter you should seek out the brown ones. The white filters are bleached and who wants bleach in their coffee? Not me!
So buy the brown filters. Your machine will take either a cone or a basket style. Check your brewer's user manual or just peek into the filter area - if it has a flat bottom is is basket style.
The other option besides paper is the gold filter. The gold filter has a very fine gold mesh and is used in drip coffee makers in place of the paper filter. Both cone and basket style are available (see below).
The gold filters work just fine but you will want to use a slightly coarser grind with them as they don't filter particles as well as paper. The resulting coffee will also have a slightly "bigger" or "grittier" mouth feel. You will also notice a sediment ring at the bottom of your mug.
Us gold filter users can get every last drop of coffee from our cup without getting that sediment in our mouth. It takes practice!
Go ahead and get yourself one of the gold filters. The reason is that you will eventually run out of paper filters and be in big time trouble when you go to brew your coffee. By having a gold filter on hand you have added a layer of redundancy to your coffee system and we in aviation are always looking to add redundancy!
Note: make sure to get the style that matches your drip brewer!