Assuming you weren't going to overclock...

[captaincranky]

But did have an app that could utilize 2 cores, (Photoshop Elements 5.0, Possibly Photoshop CS3), What are some best guesses for the price vs. performance "sweet spot" among these chips: (I'm running DDR2 667MHz RAM and not likely to change it).

C2d 4300 "Allendale" ($114.50)
C2d 4400 "Allendale" ($139.00) < My guess 1 (does the cache size matter that much?)
C2D 6320 "Conroe" ($168.00)
C2d 6420 "Conroe" ($189.00) < My guess 2 (4MB L2)
C2D 6600 "Conroe" ($227.00) < Damn that's cheap

These new prices are starting to have a real built in "wow" factor!

 

[LinkedKube]

the sweet spot, huh, its the 6600 by far.

 

[gavilan]

yeah, definitely go for the 6600 Conroe. Best bang for your buck.

 

[CMH]

zzz... The E6600 is not the best bang for buck IMO.

Usually the slowest of the series is the best bang for buck, so I'd be inclined to say E6320. The E6420 isn't too far behind, if it is at all.

But you might need the extra performance offered by the E6600, and since its not really much more expensive, you should go for that if your budget allows it.