My favorites...

HKG, SYD, HNL, and SIN in the Pacific Rim.

LUX, MXP, and DXB in Europe and Middle East.

Even places in Africa can be good layovers with the right crew...you can always get together for drinks and dinner in a good hotel in Nairobi, Johannesburg, etc. And a lot of us have done at least the day safari somewhere in Africa...and some have done overnight ones also.

This month for me is as follows...

I'm in DXB on Day 3 of the first trip...

Day 1 DH from home to CVG
Day 2 Operate CVG to BAH, DH on EK to DXB (Business Class), 18:50 duty
Day 4 Operate DXB to PVG, 31 hours layover
Day 6 Operate PVG to DXB, 16 hours layover
Day 7 DH on EK DXB to HKG (Business Class), 22 hours layover
Day 8 Operate HKG to CVG
Day 9 Go home for 14 days

Trip 2 this month...

Day 1 Operate JFK to ANC, 26 hours layover
Day 2 Operate ANC to ORD, 29 hours layover
Day 3 Operate ORD to MIA.
Day 4 go home
Day 5, and 6 on "R1" (Residence Reserve)