The stock heatsink at idle isn't terribly loud, but if you are cranking on something intensive it can get fairly noisy.
If you don't feel like spending $50 on a top end heatsink, get the Coolermaster Hyper 212. Normally about $30, but $18.99 at this link:
http://www.jr.com/cooler-master/pe/C...tJEAnvsOCqHiOA
Its not THE BEST for cooling performance, but its the same general design as everything else and is therefore a good, decently competitive solution. Its also possible to mount a second fan for more performance and/or more silence.
*if you aren't concerned with gaming, the built in video for the Asus mobo handles Blu-ray and HD video perfectly.
Right now the two best mid-range deals on gaming cards are ATI/AMD Radeon 6850 or Nvidia's GTX 460. The performance is very similar, as well as the price. Really it comes down to feature preference specific to the brand.