There can be a lot of hubub about the whole Xigmatek Gaia versus Coolermaster 212 EVO. You'll find bench mark reviews where one one-ups the other, and, more often, where the difference between the two is practically negligible. The respective buyers of each seem satisfied with their purchases. Honestly, I think the nod probably goes to the 212 EVO, and it is probably the safer buy. It has a newer heatpipe design configuration. If I only cared about saving money, though, I would probably go with the Gaia; right now it's 25 bucks on newegg, which is 10 dollars cheaper.
Personally, I currently have an Enermax ETS-T40-TB installed. It, too, costs 35 bucks and, overclocking aside, it is another option.
If optimum quietness is preferred, the Arctic A30 Freezer, which I also own, is ridiculously quiet. It often goes on sale for 30 bucks on newegg, and for that price it can be worth it. The downfall is that it can only hold one fan, but regardless, it still holds its ground. Alternatively, you could just by some Arctic F12 PWMs, the fan it uses, and stick those on your heatsink. They cost only about 10 bucks each.