As a newbie, I find it very easy and alluring to fall into the trap of stretching my budget and buying the most expensive specs i can afford. i feel like i have an angel whispering in one of my ears to go for performance/price while the devil is whispering to go for performance on the other.
I need you to help me find a balance. I want to maintain a good price/performance ratio while still being able to handle the current games out there (crysis) and the games to come (starcraft 2, diablo3).
Well, you wont be overclocking at all on an Intel board. For gaming, you really can't beat the price on an E8500, except with an E8400 if you're not overclocking by a lot. Perhaps step the board down to an X38 or P45 if you're going for cheap. At the very best right now, I'd either SLI two 8800GTS's or just go with one 4850 and grab another down the road when possible and crossfire them. DDR2 800 is fine for general purpose overclocking, but if you're trying to squeeze every ounce out, look at DDR1066. IF not, stay with 800. Boosting your FSB on an 8500 to a respectable 400Mghz will give a 1:1 ratio with your RAM (Good) and will get a substantial OC of about 3.8Ghz, which can be cooled easily on air.
After reading your post over, if you really want the best bang out of games like Crysis, crossfire two 4850's. It wont be as good as two 4870's, but the difference in performance is negligible. However, the difference in price, is not. With that set up,or even with just one 4850, it's more than enough power for a 24" monitor. Unto future Blizzard games. I've been a loyal Blizzard fan for years (minus WoW), and one thing that Blizzard does, which is so intelligent and why their games don't die, is that they go for scalability (reaching a larger market) over intense graphics (pricey, only for that "elite" niche of gaming.) I'm very confident in saying this because that's how it's always been. I'm sure you'll see plenty of the newer AMD boards with on-board-graphics chips that will handle D3/S2 adequately. And if by some off chance that I'm wrong, you'll have two HD4850's under the hood to serve me justice.
^+1 , there's a middle ground. E8500 is a good choice, just a small step higher then the E8400. The Q6600 is also an option if you overclock it to 3.2GHz. Between the P35 and the X48 boards is the P45 with limited crossfire. Available for about $125 it will give you the option to crossfire 2 4850s. So price/performance with the E8500/P45/and 2 4850s is excellent. 2X2 GB of DDR2 800 1.8v is all you need unless you're an extreme overclocker.