My best negotiated incentives package was during my work in Saudi Arabia.

In addition to all the normal stuff like compound housing, meal allowance, etc. I was assigned a personal bodyguard/translator/facilitator (a great big hulk of a guy, George, a wonderful gentleman from Egypt), plus 5 days per month anywhere in the world including First Class airfare (usually taken in Europe), and 2 weeks per Quarter vacation including First Class airfare anywhere in the world.

You see, as a expat single man living in Saudi Arabia, there are not many, how do I say it, "opportunities" for "social interaction" with members of the opposite sex.

These were considered "mental health" perks.

I didn't always use some of my travel package as the normal course of my work took me traveling quite a bit, and I would often combine work and pleasure trips into one, saving the boss the additional separate airfare (not that he really needed the money from the savings).