There are three types of filters commonly used in Freshwater setups.
a) A Hang on Back Filter (HOB for short) such as Aqua Clear and Penguins and Whispers are common. These are the cheapest to purchase and are commonly used in tandem with a canister filter. They are simple to use and typically hang on the back of your tank. The general rule with HOB filters is to filter water at a rate of ten times the tank size per hour. Example if you have a 100 gallon tank you would need to buy enough filters to mover 1000 GPH to have sufficient filtration
b) Canisters - (eg. Fluval x04 Series, Ehiem, Fillstar XP Series )These filters are moderately priced but offer excellent filtration and options for media in them. It is highly recommended that you buy a Mid-size canister and use in combination with a HOB. The are far more superior than a HOB but offer a small water filtration rate. The most common setups you will find will include a large HOB filter and a mid-sized canister setup and this is what I recommend as well, it’s the most bang for your buck. The rule of thumb for canisters is 3-5:1 unlike a 10:1 ratio of HOB for filtration.
c) Wet/Dry Filters or Sumps - These are becoming more popular in freshwater tanks and are the best on the market you can buy but for a price. They usually use a bio-tower similar to a canister as well as well as a dry fiber/floss filter pad on top. The rest of the area is used for the sump area and provides a place for submersible heaters and water return pumps and chemical filtration. They are very expensive to buy although there is some good Do it Yourself articles on building one of you own if you are handy.
Whatever you buy, remove the carbon! Only use carbon media to remove medications. Replace with sponge media or other bio friendly media to encourage bacteria growth.