First time builder looking for some help

I'm looking at building my first computer and need some help. I'm looking at building a mid-range rig for gaming and if that goes well, building another faster machine down the road.

This is what I am thinking:

Intel Core 2 Quad Q9300 Yorkfield 2.5GHz 6MB L2 Cache LGA 775 95W Quad-Core Processor $239.99
http://www.newegg.com/Product/Prod [...] 6819115043

GIGABYTE GA-EP45-UD3R LGA 775 Intel P45 ATX Intel Motherboard $119.99
http://www.newegg.com/Product/Prod [...] 6813128359

Crucial Ballistix 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory $41.99
http://www.newegg.com/Product/Prod [...] 6820148212

SAMSUNG Spinpoint F1 HD753LJ 750GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - OEM $74.99
http://www.newegg.com/Product/Prod [...] 6822152100

CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Power Supply $119.99
http://www.newegg.com/Product/Prod [...] 6817139006

LG Black 22X (CAV) DVD+R 8X DVD+RW 16X DVD+R DL 22X (CAV) DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 22X DVD±R DVD Burner $22.99
http://www.newegg.com/Product/Prod [...] 6827136152

ASUS EAH4850/HTDI/1G Radeon HD 4850 1GB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card $189.99
http://www.newegg.com/Product/Prod [...] 6814121278

And an Antec 900 case. (I've already purchased the case.)

Anything I'm missing or should change out?

I want a Quad Core, but I am not sure which one gives the most bang for the buck currently.

Your help is appreciated!

Pho

The RAM is the only really bad choice. Crucial has fallen out of favor in recent years, but beyond that 2.0V on 800Mhz is unwarranted.

For just a couple dollars more, this G.skill will do the trick:
http://www.newegg.com/Product/Prod [...] 6820231209

If you upgrade to a crossfire board, you'll keep the option of adding a second video card in the future:
http://www.newegg.com/Product/Prod [...] 6813128358

That's a very nice PSU, but it's far more wattage than you need, unless upgrading to a crossfire board. Save 20 bucks and get a 650TX:
http://www.newegg.com/Product/Prod [...] 6817139005

It's a tough call on which quad is the best bang for the buck. Probably it's the Q9550:
http://www.newegg.com/Product/Prod [...] 6819115041

At that price, a 512MB 4870 would be a better deal. All three of these offerings by Sapphire are excellent, and you'll get excellent return on your investment from any of them:
http://www.newegg.com/Product/Prod [...] %20Limited