Eheim canister filters are great... You can even get models with built-in wet/dry filters and heaters :-D
If you go with a Hang-On Box filter (HOB), I'd say Aquaclear is the best. Simple design, but that's why it's better than the others and works great. Foam blocks and media "pillows", rather than those flat/thin little sleeves (hate those) which force you to use carbon (the carbon comes built into the filter cartridge). Many fishkeepers don't use carbon, as it is usually a substitute for proper care. Also, you can rinse/ring out the foam blocks almost indefinitely, instead of having to buy new all the time with the others. As well, if the carbon is built into the cartridge, you must buy new ones as the carbon becomes saturated with the toxins and then starts to leach them back into the water.
There are probably others that would be worth mentioning, but I can't think of any ;-)