I use this penn plax cascade filter, and have been for the last 2 years and it works great, even on my heavily stocked 75g I never see amonia or nitrItes...so I know its workin good!
I have a 3 month old Cascade 1200 for sale if you are interested. It's a little
too tall to optimally fit under my 125 gallon setup because of the raised
bottom section of the metal stand