CPU choice for a new development machine?

[Shroud]

I chose an AMD Socket 939 chip for the last machine I built figuring I'd save myself a few bucks. As a result, I boxed myself into a corner when it comes to considering a CPU upgrade.

I'm considering an upgrade of the following:
1) mobo
2) CPU
3) RAM - most likely 4gb, upgrading to 8gb down the line

My question is this: If you had to choose between the LGA 775 (ie Core 2 Duo/Quad), LGA 1366 (i7), or Socket AM2+ (Phenom) then what would you choose?

Is there still sufficient life left in the lifecycle of the Core 2 chips to make them a decent choice still?


note: Thanks to Tom for activating my account. I've been reading the forums for a longtime.

[mono]

If you've made it this far with a Socket 939 board, you might be fine with LGA 775, which is what I'd suggest among your listed options. Prior to the release of Nehalem, C2D or C2Q processors have easily been the fastest, and will likely give you more bang for your buck as i7's become more prevalent and prices fall.

That said, if you can scrape up the cash for the entry level i7 920, you'll be set for a long time.

[Coca Cola Zero]

I'm still very happy with my Core 2 Quad machine as a development machine, 8 gb of memory and Vista 64. You can probably get one just like mine for like half of what I paid for it earlier this year.

If I were buying today I'd be tempted to go up to the i7 though and it would come down to speccing out a machine of each core type and seeing how big the price difference is. The i7s themselves aren't too expensive for new chips but the DDR3 requirement, the more expensive motherboards plus the fact that I wouldn't be willing to deal with less than 6 gigs these days would probably be the potential make or break cost decision.

[Charles]

Go 64 bit so you can have lots and lots of ram and thus compile to a ramdrive. Instant compiles = win!

[spiffy]

Shroud, I basically upgraded from exactly the same situation this black friday when prices were good for buying parts. I considered the i7 chips, but seeing as the mobo and ram were twice the price and even more when compared to sales on socket 775, I put together a core2Duo machine that shreds every game I've thrown at it for $1000 (including a 24" screen, minus the cost of a case and hard drive).