depending on what size you have, I really like Aqueon, they make good products, although I have never tried their filters.
The best filter I have found, and I absolutely love it is the Fluval Aqua Clear, It comes with 3 seperate inserts, the BIOMAX layer, a Carbon layer, and the Mechanical filter layer, whats good about this one is the water flow is adjustable, (40-70 gallons) and you can buy additional inserts as well, (Up to 5, comes with three) I just added the ammonia reducing insert into mine. It is a great filter, I absolutely love it, got it for $50 USD. I also really like my marineland penguin 200. But I am absolutely in love with my fluval aquaclear, the only downside is that the replacement filters are a bout $4-$5 a piece, and your only suppose to change one at a time, so it can be a process maintaining all the right filtration devices, I just rotate mine from the bottom up every 2 weeks, so I have replaced the whole filter every 6 weeks.
The ammonia remover insert actually removes ammonia, its not one of the ones that chemically binds with it making it save, but still tests for it. This one actually decreases the amount of testable NH3/NH4 ya, great filter.