The key to these machines is using a gold, nylon, or other type of permanent filters. Permanent filters make sure that the flavor molecules from the coffee grinds pass through into the water, but more importantly, the permanent filters do this without adding unwanted flavors. You may have to clean the filters after each use, but this little bit of extra work is well worth it.
What is wrong with paper filters for coffee machines? They impart an aftertaste into the finished product, and they absorb some of the special flavor molecules and aromatic oils from your coffee beans, which are what gives your cup of joe its tantalizing taste. Rinse paper filters with hot water before using them if you must. This will wash out some of the aftertaste.
Checkout coffee machine for your modern kitchen here