Looks like I need to replace the pump on my aerator.  Any suggestions on what brand to buy?  I will definitely want to buy a brand that sells the cartridge style pump where you can just pull out and replace the pump only if it goes bad.  Attwood, Rule and Johnson seem to be the most common brands.  Attwood looks the cheapest which is a plus, but want quality as well so was leaning toward the Johnson.  Any help would be appreciated.

Had to replace mine a few years ago, went with attwood and have had no issues. Wish i would have gotten one size larger though. Get the biggest size your plumbing will allow. 

I haven't heard of any issues with any of them.

Johnson cartridge pump i changed all mine out this week took about an hour to change 4 pumps