I have read the RAM sticky and I was wondering which of the timings
(5-5-5-12 or 4-4-4-15- for PC26400 DDR2 800 RAM) are generally better to pair it up with a Intel C2D? The guide (which is really helpful) states that the first timing (CAS Latency) is one of the most important things to consider in RAMs, but would the last timings (12 vs. 15) have a major effect? Also, if I were to overclock an E6600 to (a very lucky) ~3.6Ghz (~400 fsb), would the two different timings have a major effect on overall performance? Also, I don't plan to overclock the RAM, unless I require to (got to read Wusy overclocking guide!!!!).
Timmings are important but you should always keep an eye on the diminishing return you get. I don't think it's worth paying a lot of money to get those extra benchmark points. If you don't plan on OCing the ram itself I would say your C2D at 3.6 with DDR800Cl5 should perform really well.
One of the great thing about tighter timmings is that you can loosen them to achieve higher frequency.
When buying the ram, you should read a lot of review and forum prior to making you decision. There is some good deal to be found. The ram I ended up getting is the following, for me, it will run at 4-4-4-12 all the way to DDRII-900 with 2.1v which is pretty decent. That is just one exemple of a nicely priced ram that will do better then what the label says