On this page I'll go into more detail when choosing the best CPU for your situation. Benchmarks are a good way to determine how certain CPU's stack up against others that are within your budget. Sometimes you'll waste money buying the fancy new i7 when last years i3 will give you the same results. Certain applications don't utilize the technology i7's have to offer, therefore the user sees no notible difference between the two types of CPU's. Below are some benchmarks showing what some more common CPU's are capible of. The ones chosen are generally popular picks in modern custom computer builds.

As you can see above, the 8350 does offer a significant performence increase over the lesser 860k when dealing with multi threaded applications. However would likely not offer much benifit in gaming. If you're on a budget the 860k is the better option.

People on a budget should look closely at the 8350 as the multi threaded workload will beat out the 6500 slightly. However the 6500 is a much more well rounded CPU.

Both of these processors are wonderful for modern gaming and general use situations. The 6600k can be significantly overclocked. Doing so will require a slightly more expensive motherboard and an after market cooler. Increasing the overall price of the 6600k by a fair amount. The performance increases wont be enormouse overall however and only the most demanding tasks will see a benifit. Examples are video rendering and games that utilize strong CPU's.

The differences between the 6600k and the 6700k are almost nothing doing normal things. Gaming and multi most applications wont see a huge difference between the i5 and i7. However the i7 will offer a significant performance increase with multi threaded workloads. In the near future more games will likely use more threads, in that case the i7 is the wiser choice if you plan on building a high (or very high) end computer.