My record was back in December 2017.
RDU - ORD - NRT - SYD (first stop) - SIN (second stop) - NRT // HND (decided to spend the night) - LAX - DFW - RDU
Was a work trip and spent ~ 28 hours in SYD and 28 hours in SIN (half day event in both) and then decided to spend the night in TYO on the way home instead of doing the straight shot (back when DL had SIN - NRT and could've continued on to the US). Left on a Sunday and got back on Saturday.
Clocked in at 26,746
A couple of months ago I did:
RDU - DTW - ICN - BKK (stop one, was there 16 hours) - SIN (3 nights) - ICN (1 night same as with TYO above) - MSP - RDU
Left on a Sunday and got back on a Saturday same as above though clocked in at a more reasonable: 20,384