Eheim Professional Canister Filters
The Eheim line of aquarium filters is by far the best on the market. They are the most durable, well made and efficient filters one can buy. The Professional series are somewhat more expensive than the Classics and I think there may be some, very little, media bypass compared to the Classic's zero bypass, but the ease of setup, use and general maintenance more than make up for this possible deficiency.
The hose connectors and shut off valves are incorporated into a single, easy to use unit, the media is in hermetically sealed trays, and because of the ingenious design the heads can be removed without any water spillage at all. I hazard to say that you could open one of these on your living room carpet with no worries whatsoever.
When cleaning one of the Classics I usually just remove the filter floss and pour aquarium water through the filter, hence backwashing any debris out into my sink. With the Pro series, one has to remove the trays and rinse the canister, but this affords a much deeper cleaning of the media. Currently I have Pros on all but one of my tanks and have never been happier with my water conditions.
NOTE: these are fairly expensive filters, about twice the cost of the Classics by the time you fill them with media, but they are extremely efficient and very, very easy to use. You will never have one of these wear out. I personally own a 2224, 2226, 2228 and a 2229. The wet/dry (2229) is very expensive but an absolutely phenomenal filter. The most efficient filter I have ever used, and I have pretty much used them all.
Hope this is useful...all I can say is the most important aspect of aquarium keeping, and the one you should be least willing to scrimp on, is the filtration system. Buy the best you can afford and you will not be disappointed.