I bought myself an HP elitedesk G3 800, they come in three skews: mini, small form factor and tower.

I bought the tower. There is so much room, I have the 250 watt PSU. But the thin is quite and simple to work on and to upgrade. Look at the Elitedesk G4 800 because there you get 8 and 9th gen intel.

But I love mine, planning to put in three large HDD in her, already have two 2.5 SSD, I have been scouting ram and got relatively cheap second hand ram deals, with 32gb in the system. I am planning on getting the 7700t (the t variant is the low power draw version).

But the thing is quiet and can be upgraded but also just plonked on a desk and left to run no worries