What were the best Core 2 duo/quad SFF (slim) desktops?

[cbn]

Makeover video for Core 2 SFF:

https://youtu.be/YyvfZ46rlaw?t=8

Spray Paint scene---> https://youtu.be/YyvfZ46rlaw?t=245 (Not sure what paint he is using, but that is the Rust-oleum comfort grip attached to the can)

Of course, these principles could be applied to newer SFF (or Tower) machines as well (Sandy Bridge, Ivy Bridge, etc)

 

[cbn]

Here is the current pricing on the quad cores:

http://www.delidded.com/lga-771-775-cpus/ (As a reference point Q9400 is now $14 shipped and the E5450 is $15 shipped)

The dual core pricing I just checked on ebay:

E8600 $12 OBO shipped
E8500 $6.24 OBO shippped
E8400 $4.05 OBO shipped

 

[cbn]

Here is a video on Q9400 vs. E8400 with GT 1030: