Well, the newest Intel socket hasn't come out yet, but there are 2 other Intel options: 2011 and 1155. 2011 is newer, and will have future support for newer processors, such as Ivy Bridge-E. The cheapest CPU for socket 2011 is the 3820, a quad-core, compared to the other 6-core 2011 CPUs. The 3820 is about $285, and performs a little worse than the i7 3770k (but better in some cases, as with most components), which is the best socket 1155 quad-core. This brings me into the 1155 socket. 1155 has been around for longer than the 2011 socket. It has been around at least since Sandy Bridge processors. The newest CPUs from Intel - that are currently out, at least - are on socket 1155; they are Ivy Bridge processors. They start with the i3 and go up to the i7 (not i7-E, which stands for enthusiast; i.e. more expensive/more powerful). An i5 3570k CPU, which doesn't support hyper-threading (virtualizing cores; i.e., makes a quad-core show up as an 8 core), and will cost about $220. Socket 1155 motherboards are cheaper, and if you plan on using socket 1155, you should go with the Intel Z77 chipset. The chipset controls the functions of the motherboard and works in tandem with the CPU on certain tasks. There are other chipsets for the 1155 socket, but Z77 is the best - pay the extra $15 for it, it is worth it. However, on socket 2011, you have a much better chipset - X79. The X79 chipset supports quad-channel memory (RAM), which makes equally clocked memory able to perform on 2 extra lanes for data transfer. Z77 only supports dual-channel, which is still extremely good. Socket 2011 is more expensive, but has more room for upgrade in the future. If you plan on keeping a motherboard through more than one CPU upgrade, 2011 is the way to go. If you use socket 1155, you are stuck with the i7 3770k (which currently murders everything - I have one in this build and I love it, but I wish I had gone with socket 2011 for upgrades later on) or some medium-end Intel Xeon processors, a CPU series intended for servers, mostly. Socket 2011 also has some in-house, high-end Xeon processors that run some of the most demanding servers out there.
If you plan on using socket 1155/Z77, I recommend going with this combination: http://pcpartpicker.com/p/75Oe
Sure, you could build the "Cheap-Ass Gaming Rig" for a little more, but this will allow you to upgrade in the future.
If you plan on using the more recent/upgradable socekt 2011/X79, I recommend one of the following combinations:
(i7 3830) http://pcpartpicker.com/p/4X6F
(i7 3930k - 6-core CPU) http://pcpartpicker.com/p/539O
The second 2011 combination is much more expensive - almost twice as much as the socket 1155 combo. However, the 3930k has 6 cores, making renderring and gaming performance faster. However, is a jump of ~$330 worth it? The price/performance ratio is not equivalent, but the performance is better. A side note - in some tests, the i5 3570k has beaten the i7 3820, but the 1155 socket is old and will not be worked on further.
For AMD, you may want to wait. The current high-end AMD socket is AM3+, containing powerhouse CPUs, such as the 8150. AMD is a cheaper company, yes - making their price/performance higher. Their overclockability(is that a word?) is very good as well. However, in my personal opinion, based on research and as little bias as possible, Intel is a better performing CPU. Even if AMD is cheaper (sometimes a lot more), I find Intel's micro-architecture to be simpler and more effective. AMD CPUs have more twists and turns; a longer pipeline. Intel has shorter pipelines, making the transfer of data faster. However, I also believe that AMD makes some great, affordable processors. At a certain point, you are paying thousands of dollars (water-cooling, 4xSLI, i7 3970X, etc.) for performance increases of miniscule amounts - $1000 more for 3 more FPS doesn't make sense. At that point, it isn't worth it. That is where AMD wins, I believe. AMD offers performance at a great price, and has enough support in the market to be competitive. If you are pressed for money, get an AMD FX CPU, such as the 8120 or 6300, and an AM3+ socket motherboard and you will be fine. Upgradability, however, will be limited with socket AM3+ - much more so that socket 2011. If you want to be able to keep your motherboard for multiple interations of upgrades, I recommend socket 2011. If you want to get a computer built soon, and with a small budget, then AM3+ is the better option.
If you plan on using socket AM3+, here is what I would recommend: http://pcpartpicker.com/p/1ZAk
Yes, it is cheaper than the socket 1155, but socket AM3+ is doomed to a similar fate of obseletion. I would recommend saving up for a socket 2011 combination, but if your budget limits you, go with AMD. I hope I helped!
Cheers,
Brennan Riddell