Dosh
Oops, someone beat me to it…
Variations of “large”: “big one”, “grand/bag (of sand)”. A “bar” (as in “half a bar”) used to be one pound, but I know I’ve heard it used for a million. Important to keep track of what industry you’re in, to avoid unfortunate misunderstandings.
Rack: a thousand dollars.
Stack: 10 racks.
Geetus–general term for money.
quatloo
(filthy) luchre
wampum
For money in general I use the totally boring bucks. As in, “holy shit! can you believe Bobbi just spent eight thousand bucks on an '86 Skylark with a blown motor and an ‘I heart John Denver’ bumper sticker in the back window??”
For actual cash I use either “cash” (duh) or more often folding green, which incidentally I picked up from one of Cecil’s columns eons ago. In our ever-increasing cashless society it’s often necessary to clarify if I’m paying for something with actual physical paper money, so folding green works well.
Interestingly, folding green is one I’ve never heard anyone else say or use. It’s also absent from the above Wiki article. Nonetheless I like it.
kablingy
(More Krusty-isms later)
“So when this drunk handed me a ten spot after a request, I couldn’t get very excited. What was it I asked myself? A piece of paper crawling with germs.”
—from Detour (1945)
The same movie makes reference to having a “lot of jack”, i.e., cash.
“Bread” dates from the sixties (at least).
Tony Soprano wouldn’t lend me a tenor. He is alto-gether bass. 
He usually wears nice shoes, but yesterday he went out in a paradigm store slippers.
Small change (du p’tit change):
*Une cenne
Un cinq cennes (pronounced cincennes) / un sou castor for kids
Un dix cennes / un dix sous (pronounced dissous) / un sou bateau for kids
Un vingt-cinq cennes / un trente sous / un sou caribou *for kids
Dollar and above:
Une piastre / une piasse / un sou canard for kids
Un cinq, un dix, un vingt
Generic:
Du foin
Du blé
Des bidous
Also, it was an actual currency, long before it was a slang term.
grand = a thousand dollars
c-note = a $100 bill
Benjamin = a $100 bill
piece of eight = a Spanish dollar, worth 8 reales.
wampum = another actual currency (sort of) that became a slang term
dead presidents
un sac, une brique, des thunes…
le grisbi, le magot… du fric
Let’s not forget Ali G and squid
Is it spelled duckets? I always thought it was ducats, after the European coins.
And has been rarely used since the Seventies. I was listening to Billy Joel’s “Piano Man” the other day, and the “they sit at the bar and put bread in my jar” line made me wonder if that would make sense to a twentysomething.
coin, pronounced as “quan,” Jerry.
Of course it makes sense - they’re all on low-carb diets except him. 
The bread was probably from that bakery the Beach Boys were working at when they recorded “I Get Around”.
(I’m a real coolhead / I’m making real good bread)
Readies. I think it is in reference to ready cash, but some say it’s from the red colour of the £50 note.
Wonga. Puportedly Australian slang, but I have never heard anyone use it unironically.