With all the irreverence I can muster… a sampling of some common and not-so-common euphemisms for died.

(I hereby grant permission to say I won one for the Reaper when my time comes.)

Assumed Room Temperature
Ate It
Baste The Formaldehyde Turkey
Be No More
Be Taken
Became A Root Inspector
Become Living-Challenged
Belly Up
Bereft Of Life
Bills Of Mortality
Bite The Dust
Bless The World With One’s Heels
Bought The Farm
Buy A Pine Condo
Cash In One’s Chips
Checked into the Wooden Waldorf
Checking Out The Grass From Underneath
Crossed The River Styx
Dance The Last Dance
Definitely Done Dancing
Dirt Nap
End One’s Earthly Career
Failed to meet their wellness potential
Fallen Off Their Perch
Finally Got His/Her Tab Called At The Bar Of Life
Go Home Feet First 
Go Home In A Box
Go Into The Fertilizer Business
Go To A Necktie Social 
Go To Davy Jones’s Locker
Going To The Big ___(Whatever) In The Sky
He Examines The Radishes From Below
He’s Juggling Halos Now
He Just Got Stamped “Return To Sender”
He’s Past His Sell-By Date
Horizontal Hilton
Immortally Challenged
In The Horizontal Phone Booth
It Was Curtains
Joined The Choir Invisible
Joined The Majority
Kicked The Bucket
Kicked The Oxygen Habit
Left The Building
On The Heavenly Shores
On The Unable To Breathe List
Permanently Out Of Print
Pushing Up The Daisies
Reached The Finish Line
Returned To The Source
Riding The Perma-Pine
Shuffled Off The Mortal Coil
Six Feet Under 
Sleeping With The Fishes
Sprouted Wings
Taken Out Of Production
Taking A Dirt Nap
Taking An All Expenses Paid Trip Aboard Stygian Cruise Lines
Tending Towards A State Of Chemical Equilibrium
That Was All She Wrote
The Big Nap
Took A Harp
Traded To The Angels
Turning Up Daisies
Wandering The Elysian Fields
Wearing A Toe Tag
Winning One For The Reaper
With The Ancestors
With The Angels
Worm Food