I wanted to put together a table with the highest & lowest density seating configurations for various aircraft.
For example:
Airbus A380-800 (Low 407 by KE, High 526 by LH)
The parameters are:
1. Scheduled passenger services
2. Service operates or operated for at least a few months
3. Cabin must have economy class
I seek your expertise & collective wisdom! Thanks for playing along

Sources:
KE A380
LH A380 scroll down to the 8F-98C-420M version
Notes:
-EK will apparently start a 615 seat A380 service from later this year
-There were once plans for UU to have 840 seats in an all Y configuration for their A380 but those have since been canceled
-Airbus recommended a 555 seat configuration for the A380 in their airport planning manual (Page 67-68 of PDF)
[Edited 2015-06-22 10:16:09]