Budget, amd vs intel + mobo and ram

Hey all,
I was planning on upgrading about 6 months ago but money was needed elsewhere. So right now i have an ANCIENT 754 board with a AMD sempron 3000+. 1 gig of ram and a 1950 ATI PCI 16 card. Actually i run steam games fine, and WoW back when i played. So now i'm ready for some real games. My daily abilities include, itunes, window's messenger, firefox w/ multiple tabs, and sometimes Counterstike or something like that. This handles it OK but can get clippy

So now that you see how desperate i am lol

My budget is around $200 give or take 30 bucks for a mobo, cpu, and ram.
So my first question is, dual, tri, or quad? for the daily use of my computer now listed above.
Doing my first bit of research i see that a AMD quad is only $90 (AMD Phenom 9600 Agena)
Perhaps the low price is for the slower clock times, but still a quad core none the less.

AMD vs. Intel
I DO NOT PLAN TO OC ANYTHING
So what is the best bang for the buck stock
If you would be so kind as to put together a barebone system including compatible CPU, Motherboard, and Ram. Around 200ish dollars, and (optional but would be excited to learn others thoughts) why you chose AMD over Intel or visa versa. and why the mobo is what you picked out if anything other than price.

Possibly one of AMD's X2 II cores look about what i might need but please educate me, i've been out of computers for quite some time

Thank you all so much, i am sure this post sounds weird reading as i am doing this quickly to find the results and order some stuff!

-Noah