I've used two different methods on my setup during the build. Each time I put a small amount on the heatsink, spread it around and wiped the excess off.
For the CPU, first time I spread the paste over the chip with an old credit card, and the second time used the single line method.
To be honest, each method gave pretty much the same result. As long as you don't use too much paste and apply it correctly according to each method, then I think the results will be on par.
EDIT Oh, the reason I reapplied was because I was expecting lower temps then I got. I actually got the temps I was looking for by tidying the cables inside the case, and setting the fans up (Antec 900 case, with several fans with speed switches), so in each case the thermal paste seemed to be applied correctly. Since I built the PC I have tried Arctic Silver 5 and Arctic Ceramique, as well as the MX-1 supplied with the Arctic Cooler Freezer 7 Pro. They gave pretty much the same performace.
