I have always been very pleased with the performance the aqua-clear filters I have used. All through my marine bio class in high school we used nothing but aqua-clears of various sizes (this is on saltwater tanks); our teacher swore by them.
Since high school, I have used an aqua-clear 50 (formerly aqua-clear 200) on my 30 gallon freshwater tank in my dorm room. I am about to get another one (as I am giving most of my fish to my siblings for christmas and they get the old filter).
The machines are robust, have a number of useful filter inserts available (ranging from activated carbon to foam chunks to special pellets designed for bacteria to live in to ammonia absorbing chemicals), and have lots of available space for bacteria to live in (the inside of the filter is completely full of available foam surface area, not just one sheet of cotton like in a normal one).
Another nice feature is that they are transparent, so you can see if there is a lot of gunk caught in them. If you shop around online you can usually find them for quite low prices, I ordered mine online for $15 from some specialty store in California. The price and performance can't be beat, personally I'd recommend aqua-clear (made by hagen) over any other brand of HOB filter. I haven't tried bio wheels so I can't speak on those, but I've had a few other small filters over the years, and my experience is that aqua-clear means quality.