I went with 32GB because that's what was in the junk drawer at work. Nice little i7 HP 800 SFF office desk top box, Put in a 480GB SSD and found a great deal on a 5TB drive.
To cap it off, installed ESXi 6.0 and have a hella nice little home lab, domain controler, FreeBSDs, file server, pfSense, FreePBX, OwnCloud, and my IBM Domino & Sametime server (that's another show.)
This desktop is also an HP with 32MB RAM & 480 SSD and two Quatro 600 graphic cards (one for each monitor.) It suits my humble needs.
The company got bought and the new parent is a Dell house so we have to "upgrade" to become standard. I can't wait until next year when all the HP Z820s Xeon workstations become available.