The only filter used on this photo is the HOB.
While I agree that visible tech is not everyone's cup of tea, if you are just getting into the hobby and have a limited budget, start with a hang on back filter. Some tips on how to make them work for you:
1. Go bigger. Always. If you have a five gallon, get a 10-20 gallon filter. Have a ten gallon? Go for the 30-50, etc.
2. Make sure it's adjustable. Since you're going bigger you may want to slow the flow.
3. Avoid filters with cartridges. While they have their place, they usually wear out quick, limit space for beneficial bacteria and need to be replaced regularly. With regular water changes, you don't need the cartridge.
4. Get ones with large media compartments. I can't say enough about this. Filters are only as good as their biological media. I prefer the Aquaclear brand as I can add the media I want. One sponge is usually enough and the rest of the space is used for ceramic rings, crushed lava rock or whatever you prefer. Have problems with algae? Consider how much biological filtration you have (more on this another time).
5. Place them where you get the most water agitation and flow. This serves two purposes by processing water more efficiently while also adding oxygen.
6. Chose one with the motor on the outside. This will save you room inside your tank and makes it much easier to maintain.
7. Leave it alone. Allow the bacteria to grow. When it comes to maintenance, the occasional scrub of the lip and tube is sufficient, don't disturb the media so much. If you use a sponge, clean as needed, but make sure it's accessible without disturbing the media.
Hope that helps! ...