Flexible hours, the main thing i've found is that managers simply just want the job done and done well, and after that they are fairly flexible with things that make for a good work life balance.
The policy changes from time to time (and person to person) but being able to work from home is a big plus. The worst things are the quarterly bonus rates.
Discount on private health cover, 4 weeks paid annual leave, 10 paid sick days annually, free training, cheap on-site masseuse, flexible work hours.
Only a discount for the gym in front of the office
They were good and have been improved in recent years.
List based on reports from current and former employees. It may not be complete.