In my 10g and long 20g I use whisper powerfilters but in my 55g I use marineland penquin powerfilter. Alright now another question for every that has voted or is going to vote do you think the filter(s) you use are noisey?
As none of the above are readily available in the average lfs in the UK, your poll is going to be very skewed.
I use external eheims and an internal Hagen Stingray for my little tank.
I use AquaClears on all my bigger tanks and box filters or small AquaClears on the smaller tanks. I also have a couple of sponge filters that I usually use in fry tanks.