What's my bottleneck?

It may be that you will have to OC the RAM to get that 1066 speed. If you know how then buy it, if not buy the 4gb G Skill off newegg for $46 bucks IMO, its ddr2 800 which is what you have now.

http://www.asus.com/Motherboards/AMD_AM2Plus/M3A/

^ that's my mother board.

Currently I have 3 DDR 2 800 (400 MHz) installed. Mobo is rated for DDR 2 1066.

Should I get two of these:
http://www.newegg.com/Product/Produc...82E16820148286

And leave two of my current sticks installed (in the color coded slots) or will that hurt me?

Well, your MoBo is undoubtedly dual channel. You should always put in RAM in matched pairs.

If you have 3 1GB sticks, you should buy 2 2 GB sticks and put those in the color coded slots and then take 2 of the sticks you already have and put them in the others. You'll end up with 6 GB total.

Is your original RAM all the same model and manufacturer? You want to make sure you use the same exact type of RAM in the matched pairs. So if, of your 3 sticks, you have 2 of the same model and one oddball, make sure you use the ones that are the same model.

You should have 4 RAM slots. Look at your MoBo's manual and look for recommended memory configurations. Put the new 2 GB sticks in the first recommended slots, and the 2 1 GB sticks on the others.

Okay,

So what about this motherboard with 4 of these? Any criticisms on that setup? $20 a stick means I could get 8gb of RAM for $80. Or should I just get two of the Crucial sticks for $60 total?

http://www.asus.com/Motherboards/AMD_AM2Plus/M3A/

^ that's my mother board.

Currently I have 3 DDR 2 800 (400 MHz) installed. Mobo is rated for DDR 2 1066.

Should I get two of these:
http://www.newegg.com/Product/Produc...82E16820148286

And leave two of my current sticks installed (in the color coded slots) or will that hurt me?

So I finally got caught up reading this entire thread...I'm sorry the OP had to put up with so much crap. First Lion says it is SWTOR and not the OPs hardware...Lion says you need 4Gb minimum, OP clearly said he had only 3Gb, Lion still argues with OP that he doesn't need to change anything and calling logic fails. Lion says his friends computer that matches his exactly except for a slower video card actually runs smoother.

I'll tell you this Mr/Ms. Lion, sounds like something might be wrong with YOUR system and instead of giving crappy advice to other people you should get your own situation fixed.

OP if you are using 3x 1g sticks that is definitely hurting you, on your motherboard 2 of the slots she be marked in some way, usually color coded to show where to identical ram sticks to run in dual channel mode, which means you have 2 direct pipelines to the CPU instead of 1. So you typically buy in pairs (unless you are using an oddball triple channel chipset).

Also when buying ram, don't buy what is labeled as the fastest Mhz or Ghz speed. IF you're not overclocking you don't need that as it ties in with the CPU multipliers and stuff I won't get into here. Typically the faster the Ghz the slower CAS Latency you will find on the ram. So if you're not into overclocking, you should find ram that matches the bus speed of your motherboard/cpu for best performance.

I'd probably go with 2 of the 2 GB DDR2 800 sticks with 2 of the sticks you already have.

6 GB should be enough.

I'm not sure about your CPU though. Your RAM is certainly low, but I don't know enough about that generation of AMD CPUs to know if it's a bottleneck for you.