^^^^ Bobby recommended the Quiet one 6000 to me for my sump application pushes great and I can barely hear it, its a great submersible pump. I don't know if this counts but if Ehime pumps are as quiet as their canister filters you cant hear them run at all.
I can only speak for the eheim compact 5000 and I cannot wait to sell one to some other mug who believes the eheim hype and replace it with the new-jet 4000 or try and find one of the others recommended on here.
I will keep one for water changes as the flow is amazing but they are anything but quiet and I have them in a DIY sponge enclosure so the pump is cut off from the glass and I can still hear it buzzing away.
I've never had anything but quiet from Eheim pumps. Of course, they have all been relatively small. For pushing any kind of water, I go with mag drives.
i have mag drives and quiet ones, and they both are very quiet, i barely hear them run when my head is in the stand. I find that the overflows and and what not cause more noise, and drive me nuts while i'm trying to sleep.
from what i see mag drives are inline and use ALOT of electricity. im in socal so our eletricity is super expensive... and wasteful...
right now looking at rio 3100 , please let me know if you think this is a bad decision, cuz its pretty good price, 65 shipped, and 70ish watts for 900gph.