As much as I hate to admit it, I'm still content with my PC (hardware-wise). I've really faced no limitations, other than running out of RAM every now and then while trying to multitask in KDE, but everything is actually going pretty swell.
....However, one of the things that I have at the top of my list to upgrade is the heatsink since I'm still using stock. I couldn't really bring myself to sink money into it since, ever since getting my new case, I haven't had any temperature issues.
I've already had a heatsink picked out for almost a year: the XIGMATEK Dark Knight. On top of it being named after one of my favorite movies of all time, it also has 5 eggs with over 500 reviews, supports a great deal of sockets (both Intel and AMD), and is XIGMATEK with which I've had decently good experience with cooling.
Cutting to the chase, I could never justify spending $45 on something I didn't exceedingly need. However, when I happened to visit its page and see that it was $9.97 after a MIR.....well, COME ON. (It was actually $19.97 yesterday but it dropped even further today.) As far as I know, it's pretty future proof as well: Sandy/Ivy Bridge use socket 1155, and Bulldozer uses AM3+ which (as far as I know) uses the same cooling as AM2. Even if it wasn't future proof, $10 is an amazing deal.
Needless to say, I'm jumping on it.
All sold out, folks. I guess it WAS a good deal.