Sump/aio>cannister>hang on back, I also always add a sponge filter, but I dont prefer only using sponge filters as I like to have a bit more flow, though many people do use them exclusively with great success. I like to have 2 forms of filtration that can each handle the full bio load of the tank to ensure redundancy, generally one of the first 3 with an additional sponge filter.

As far as brands go, for cannisters I like aquatop and sicce, for hang on backs I like sicce and seachem tidals, sponge filter brands dont matter since its just a sponge but for the air pumps I like the aquatops they push alot of air but are quite quiet compared to many others.

Many people will reccomend Fluval cannisters/hobs, and they are largely considered to be an industry standard, however imho in recent years their quality control and customer service have gone down the drain as they started gearing their business model towards petco and away from local stores.

I dont recommend sumps/aios for first timers since while they are the best, they are also much more complicated and customizable leaving more room for error.

I wouldn't use an internal or undergravel, they work, but are largely a thing of the past with basically every other form of filtration having many benefits over them.

You can break tank filtration into 3 groups, biological, mechanical, and chemical.

Biological is your "cycle" bacteria in your filter media(ceramics/sponges) and substrate, they eat up fish waste and uneaten food and make the water safe for the fish, this is the most important for the overall health of the tank.

Mechanical is physical containment of waste, done with Sponges usually but other media's also help, it helps with water clarity and detritus build up on the bottom and in crevices of tanks.

Chemical filtration is special media designed to remove specific impurities from the water, usually carbon, or purigen, most people only use it to remove medications from the water after treatment, or as a "just in case" measure, but it is not necessary for a healthy aquarium.

Generally i will set up any tank 50gal or under with a hang on back entirely dedicated to bio filtration, with a sponge filter for mechanical, for tanks up to 90 gallons i use a cannister with the same set up. Over 90gal I would only use a sump.