Guess that has to be my main server, even though it's a few generations older than my desktop, it has more cores, more IO, more memory and more storage. It runs FreeBSD.
Case: SuperChassis 745TQ-R800B (pic)
Motherboard: Supermicro X8DTN+
CPUs: 2 x 6-core Xeon L5639 @ 2.13GHz
RAM: 144GB - 9 x 16GB DDR3-1333 ECC Reg
Primary Storage: 2 x SanDisk Extreme Pro 960GB, ZFS mirror.
Mass Storage: 6 x 5TB Toshiba MD04ACA5, ZFS 3 x mirror.
Disk controller: IBM M1015, seems one of the most favoured HBA's these days.
Keyboard: NTC KB-6153EA with clicky White Alps.
I play with search engines and stuff, the memory comes in handy and I got it for a great price.
Desktop is a 32GB ECC quad core Haswell Xeon mumble mumble running Windows 8.1, with a pair of 30" 1600p monitors and a 20" 1600x1200. Nice having space to put stuff. Also nice having memory that doesn't silently corrupt itself every few months, you crazy kids and your non-parity.