Percentages allocated for build

[coco savege]

Given that you already have an OS, Keyboard/mouse, and monitor, what percentage of your budget do you allocate for each of the following. Assume this build is primarily for gaming.

Case
PSU
Motherboard
Processor
Memory
Graphics card
Hard drive(s)
CD/DVD

 

[0gab0ga]

prioritize quality (therefore cash) like something in this order for a gaming build:

gpu (suggestion: 8800 GTS 512 (or GT)
psu (depends on how big your build is, but corsair 620hx is a good choice for 115$ which will be adequate for most)
processor (new 45nm or q6600 or older dual cores, depending on budget, a cheap cpu can often be oc'ed to high levels)
mobo (dependant on processor, but value quality. for a budget go p35, higher range go x38 or 780i if sli)
ram & hardrive(s) (ram dependant on mobo, ddr2 800 should suffice (or 1066 if oc'ing alot). get the storage you need, 7200.11 hdd's are new and fast, but more expensive than 7200.10)
case ( some would put this higher up for looks, but make sure it has good reviews, good cooling and space ex. antec 900, coolermaster 690)
any accessories
this is the order i went, but it all depends on your budget or other preferences. others might prioritize differently. when everything is brand new you can get all the parts for a good, mid range (still plays games high) gaming computer for around 1000$ (excluding monitor and os) but whatever way you go, there is no point in buying something extremely good and something that sucks, this will just bottleneck your system anyways. therefore the order is somewhat relaxed, and too some extent should be prioritized equally. parts are prized differently. gpu's and cpu's tend to be the most expensive. the gpu is the thing that will give you performance in games. always remember that the psu powers the system. a cheap one may make the whole thing unstable or even ruined. for suggestions on builds look at other peoples threads around your budget.
also look at ati/amd options

 

[outlw6669]

Not so much on percentages.
For a gaming rig I would prioritize it in the following order:

1: GPU
2: PSU
3: CPU
4: MB
5: Every thing else

Your biggest boost is going to be with the graphics card. You should get the best you can afford. ATI's 3870 and 3870x2 are excellent choices as is any of the nVidia 8800/9x00 series with heavy preference towards the new G92/94 based boards.

The PSU should be the best quality you can find and afford. Remember that if a cheap PSU fails, it can take the whole system with it. See the PSU sticky and the Tiered PSU list to help you with your best choice.

You can generally make some sacrifices with the CPU, especially if you plan on overclocking. If you are on a tight budget, I would recomend an AMD x2 5000+ BE. If you have a larger budget, an Intel E8400 or Q6600 would work great for you.
If you are going to overclock, make sure and get an after market cooler. The Turniq Tower, Zalmin 9700, Scythe Ninja and Freezer 7 (if you are on a budget, I personally don't like the mounting) are all excellent choices.

I am sorry to say that I don't have to much experience with recent AMD MB's so I can not offer any recommendations on them as of now. On the Intel side, almost any modern MB will do. Anything based on the P35, x38 or x48 will treat you fine. If you have the budget and plan on using SLI (for nVidia cards) you will need a nForce 750i/780i/790i MB. Cross Fire (for ATI cards) will work on any of the Intel based MB's that have 2 16x PCIE slots. If you plan on going this rout, I would recommend an x38 or x48 MB as they have 2 full PCIE 2.0 16x lanes (very good). The brands that I would recommend you to chose from are ASUS and Gigabyte.

Memory is cheap. Don't worry about spending to much on anything faster than DDR2 as you will not see any real world increase. I can not recommend DDR3 at this time as it generally does not perform noticeably better than DDR2 and it costs a boat load more. The general rule of thumb with memory is that more is better.

As for the rest, get what you can afford. You could get away with the cheapest DVD/RW drive you can find (sATA is perferd) and same with the case (even though you won't... Some of them are to ugly for words).
When it comes to hard drives, I prefer Western Digital but you should go for what ever is on sale.