I realize this is a dead post, but someone may run across it anyways, so here is my 2 cents:
Modern stock coolers are quite silent, and will be drown out by almost any other fan in your system, especially crappy power supplies, stock case fans, and jet engines attached to your graphics card. So replace those other noise violators first. However, if you have a quiet system already then intel fans can be very grating on the ears because the sound they produce is more like friction instead of airflow. So if you have a fan-less GPU, and a quiet PSU then the stock cooler must go!
Here are a few tips on picking one out:
1, size doesn't matter, almost anything will cool your cpu at stock speeds. Material will make a difference, so go with copper over aluminum if in the price range, but unless you are severely over clocking the system then you don't need a big block. Keep in mind that anything under 38*c is perfectly fine, and almost anything can do that with minimal effort. I went overkill on my system and got a huge Zalman monster which keeps the CPU at 24*c for both idle and loaded temps at stock speed, and up to 28*c over clocked. It is pretty, but I do have a little buyers remorse on the price. For clients I usually get little low profile things with a quiet fan which keeps their systems in the low 30s. It's not super cold, but plenty quiet, which is the point. Obviously if you are running a maxed out Core i7 you want something big, but for the rest of us running C2duo, C2quad, i3, and i5s there isn't much point.
2, it's all about thermal paste application. Some people swear about a particular brand of thermal paste, and I am sure there is some difference, but it really is negligible if you apply it right. Spend about $3-5 on a name brand tube and it will last you about 10-15 applications. Thermal paste is not a heat sink, so don't use it as one. Only use about the size of 1/2 a pea in the center of your CPU, then use a vinyl glove and spread it with your finger over the surface so that there is a very thin layer. Air is a poor conductor, all that thermal paste does is keep air out of the little grooves and imperfections of the 2 surfaces. I find that using cards never works evenly enough, and makes more of a mess than using your gloved finger.
3, noise is in the fan. The whole reason you want to replace the heat sink is because of the noise of the fan, so spend your money on a good fan, not a big block. Anything will move air, so go as big as you can with a low RPM/Db within your price range and all will go well. Also, the slower the air movement, the less dust collection. So you want it to move enough to keep things cool, but slow enough to not attract more particulates than necessary. Also, keep your tower off the floor to reduce dust collection. Put it on your desk, or a platform, even a shoe box will help a little, but the further from the ground (and from fresh air sources like windows and doors) the less dust will accumulate. And always take a can of air to it every year religiously.
Keep those 3 things in mind and you will have new complaints about your HDDs being too loud, or the HVAC, or the traffic outside, or the 60 cycle hum of the power lines in your house, and those are wonderful problem to have! Good luck!