Thought I'd give some trial and error advice for people searching in the forums and noobs like me..CPU cooler, case fan, ram...stuff I had to figure out.
I bought the Gelid Slim Silence I-plus to replace the Intel CPU cooler (way to loud and hot). I was looking for something that would cool adequately, but was silent (this was with trmentry's advice). If you are looking for a good, very quiet fan, GET IT. It is very slim, leaving plenty of space between the PSU and the fan. My temps run at about 39-40 when not active. I opened every application I could and also ran Geekbench and Cinebench. Temps went up to about 65 tops under high stress. This was with imovie, itunes, iphoto, mail, safari playing a vid, plex playing a movie, Toast burning a DVD, and about 8 more applications open. I will say this, the fan is tiny on top. Kind of inset into the cooler. It doesn't move as much air around the case, so my hard drive temp when up a few degrees, stays around 42-45. Not bad, but something to note. Also, I have the fan set to silent mode in the BIOS....dropped temps about 5-10 C over the stock fan, and this thing is SILENT. If you put your ear up to it, you can hear it, but it is barely audible. Definitely a buy.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835426028
I was running higher temps with the stock fan ( I think the crappy pins were part of it), so I also had ordered the Silent 120mm Sickleflo case fan. My advice...don't buy this if you want quiet, which many of us need as this is an HTPC for us. It isn't loud, but it's too loud to sit by the TV. I would say its about as loud as the stock intel cpu fan at higher temps, and definitely not silent. Too loud for me, returning.
Lastly, Ram. This build would not start for me, just a reboot loop. I couldn't figure it out for awhile, and then I started playing with the ram. 1 stick was bad. I have seen this problem addressed quite a bit in this forum. I know mine was bad. So try alternating one stick of ram in both slots, instead of both at first boot.
Everything works perfectly now, love the build, fast, pretty cool, and silent.