Putting this one together for the GF.  Hoping everything will fit, play nice, not blow up.  That sort of thing.  
 
Case and PSU combo: (Is it a Coolermaster PSU?  I don't know how to tell)
COOLER MASTER Centurion 5 red version FR-T05-URI-GP Black / Red Aluminum Bezel , SECC Chassis ATX Mid Tower Computer Case with AC connector 430W Power Supply - Retail  
 
http://www.newegg.com/Product/Prod [...] 6811119153
 
HD:
Seagate Barracuda 7200.10 ST3250410AS 250GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM  
 
http://www.newegg.com/Product/Prod [...] 6822148262
 
Choice of Video Cards:
EVGA 384-P3-N853-AR GeForce 8800GS Superclocked 384MB 192-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail  
 
http://www.newegg.com/Product/Prod [...] 6814130333
or
 
EVGA 512-P3-N800-AR GeForce 8800GT 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail  
 
http://www.newegg.com/Product/Prod [...] 6814130357
 
Little worried about the 384MB of the 8800 GS.  Game interest is mostly TF2 but she likes all kinds of stuff.  I also want this to last her a while.  Thats why I am looking at the 8800GT.  Not much needs to be said about this card.  The dual slot cooler looks like a smart upgrade.  Anyway, with budget just ahead of performance and future proofing in mind, what do you guys think?
Also, target resolution is going to be 16X10 or 14X9.  19" or 22" LCD.
 
CPU:
Intel Core 2 Duo E4600 Allendale 2.4GHz LGA 775 65W Dual-Core Processor Model BX80557E4600 - Retail  
 
http://www.newegg.com/Product/Prod [...] 6819115032
 
Might take the CPU closer to 3.0 Ghz in the future.  Is the stock cooler gonna handle that or should I keep an aftermarket model in mind?
 
RAM:
WINTEC AMPX 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model 3AXT6400SE5-2048K - Retail  
http://www.newegg.com/Product/Prod [...] 6820161229
 
MOBO:
GIGABYTE GA-EP35-DS3L LGA 775 Intel P35 ATX Intel Motherboard - Retail  
http://www.newegg.com/Product/Prod [...] 6813128337
 
Cant beat this mobo.  
 
 
Total is $640-660  not bad for all that power.
 
What do you think?

8800GT don't even think twice about it . The PSU will do just fine.  You might need another CPU cooler but thats something to concider later. Ram concider G.Skill its little bit more but I belive its a better quality RAM. Good luck.

Look at this case, the Antec NSK4480.  It comes with a 380W Antec PSU.  For a single GPU, this should hold you for a while.
 
Also, if you want to overclock, get an aftermarket cooler.  You can do low level overclocks with the stock cooler, but stability and reliability are much improved with a little extra money.  The Xigmatek HDT-S1283 is rock solid, and only $37.  Easy to install as well.
 
Get the 8800GT.  It uses the newer core (G92) and has a performance increase over the 800GS that is worth the $50.  You can pick at other choices (HDD, RAM, etc..) but what you have chosen is good.
 

Coolness.  This thing is gonna kill at TF2.  

I say..
mmmm....can you still afford a better memory? like corsair, crucial, patriot, mushkin or kingston? I don't know 'bout wintech, and G.Skill...
Tips : look for a 4GB bargain, who knows that you'd ended up using 64bit OS. If I were correct, the 4GB DDR2 800 CL5 Mushkins price should be somewhere only a very little bit higher than 2GB DDR2 CL4 Crucial ballistix.
 
Have you take a look at Seagate 500GB 32MB 7200.11 price near you? I've bought it only about $10 (5 Euro) more expensive than Seagate 250GB 16MB 7200.10 (perhaps it was on clearing sale).
 
Since you are gonna OC your proc than go for Zalman CNPS9700LED (By me, Q6600 runs at 3GHz with no higher than 49'C with 80% max rpm).
 
Coolermaster cm690 is far better than centurion 5 series, and it is under $100. Combine it with PSUs from Corsair, Tagan, Enermax, and Antec that are the only good PSUs I have ever knew.  
Or you can get Antec Sonata III (bundled with 500W PSU).
 
What are you thinking?! of course! 8800GT is way better than 8800GS!
 
The rest is good enough, but care to go quad?
 

You just added like 200 bucks to my lineup.  I am looking at new memory and possibly a new HDD.  Maybe going with the suggested Antec/Psu bundle
 

Case: Cooler Master Centurion 5 or 534 your choice - $50+16ship
 
CPU: E7200 check out review here - $133 retail
http://www.xbitlabs.com/articles/c [...] e7200.html
45nm with 2.53ghz and can be easily oced to 3.8ghz with good air cooler.  
is $135 at newegg
http://www.newegg.com/Product/Prod [...] &Tpk=e7200
 
MB: GIGABYTE GA-P35-DS3L  $90  
everybody recommends this one mostly and theres a good reason why  
good overclock  
 
RAM: 2x 1gb ddr2 800 all good your chocie, most recommend Crucial brand but they got cheap with chips - should be $50 or lower
   
CPU HEATSINK: http://www.newegg.com/Product/Prod [...] =hdt-s1283  
as recommended before - $37
 
Seagate 7200.11 500gb - $100
http://www.newegg.com/Product/Prod [...] 6822148288
great speed and space
 
XFX 8800GT 512MB with COMPANY OF HEROS (great game) - $150 after rebate
http://www.newegg.com/Product/Prod [...] 6814150252
 
DVD Burner - $30 your choice
 
Power Supply - http://www.buy.com/prod/corsair-vx [...] 52646.html
should be enough juice - $70  
 
Total: $750 sorry for going over the budget, was trying to make the best bang for buck one.  I thought it would be lower.  Well I just made this list, hopes it helps.
 

^...Seagate 500GB 7200.11 for $85 at zipzoomfly.com