CPU: AMD Threadripper 1950x ~4Ghz
FAN: Noctua NH-U14S
MOBO: Asrock Taichi X399m
RAM: 64GB RAM Corsair DDR4

STORAGE:
SYS: 512Gb Samsung 970 Pro NVME
DATA: 2Tb Seagate Firecuda sHDD (8Gb SSD cache)
TEMP: 1Tb Samsung QVO SSD

VIDEO: AMD Radeon VII 16Gb VRAM
AUDIO: Asus Essense STX II
SPEAKERS: Edifier R2800
PSU: 750Watt SeaSonic Titanium
CASE: Fractal Design Meshify C Mini Dark
MONITOR: NEC PA301W
KEYS: Topre RealForce RGB
OS: Windows 7 SP2+ x64 ENG

No pix at this time.

My daily driver is an HP EliteDesk 800 G1 Tower. It's a business refurb that I bought for around $300. Came with an i5-4590 and a 120GB SSD. The only changes I made were:
-replaced SSD with a 500GB Samsung 850 EVO
-added a 2TB WD Green
-upgraded the RAM to 12GB dual channel
-added an Nvidia GTX 1650 Super (required SATA-to-PCIE adapter to provide external power as the PSU doesn't have a PCIE power connector)
I specifically picked the 1650 Super as it's easily the most powerful graphics card with a TDP of 100W or less. You see, this system has a proprietary, non-upgradeable 320W PSU.

daily driver is an almost ancient Thinkpad T420... planning an upgrade this year. But with an SSD, docking station and external monitor, the T420 is actually fast enough for everyday things, including programming...

A battered old Supermicro server from 2009 I picked up for pennies on fleabay. I don't play any modern games or do any heavy number crunching (aside from a few big Excel sheets) so it suits me fine:

733TQ-665 case with PWS-665-PQ PSU and X8DAL-i motherboard
Dual 3.6 GHz Xeon X5687 CPUs
48 GB DDR3-1333 registered ECC RAM
Blu-Ray drive
1 TB SSD + 9 TB of RAID 5 HDD storage
Windows 8.1 Pro
2 GB GeForce GTX 760
USB 3.0 PCIe card
Integrated Realtek audio and Gigabit Ethernet

I also tried to put in a SATA-III card but the BIOS didn't like it. (It only works if I disable the integrated RAID 5 controller, which I don't want to do.)

ETA: A year on, and I'm still using this old thing. These are the current specs:

733TQ-665 case with PWS-665-PQ PSU and X8DAL-i motherboard
Dual 3.6 GHz Xeon X5687 CPUs
48 GB DDR3-1333 registered ECC RAM
Blu-Ray drive
1 TB SSD* + 12 TB of RAID 5 HDD storage
Windows 8.1 Pro*
2 GB GeForce GTX 960
USB 3.0 PCIe card
Dell PERC H700 SAS-2 controller
Integrated Realtek audio and Gigabit Ethernet

* It now also has an Icy Dock MB996SP-6SB with three bays connected to the SAS controller and three to the SATA controller. I actually have a bunch of different operating systems on SSDs and switch between them as needed. Windows XP runs very well on this rig.