Cockney Rhyming Slang

Why is a Bronx cheer called a "raspberry"?

Why do you "put up your Dukes" to fight?

Why is money referred to as "bread" by gangsters?

Why do you get "creamed" when you're beaten?

Source

Examples of Cockney rhyming slang, or phrases inspired by it, are:

A

Adam and Eve = believe = as in "would you Adam and Eve it?"
Almonds = Almond Rocks = socks
Apples = Apples and pears = stairs
April = April in Paris = Aris = Aristotle = Bottle = Bottle & Glass = Arse
Aris = Aristotle = Bottle = Bottle & Glass = Arse
Artful Dodger = lodger
Ascot Races = braces (called suspenders in the U.S.)
Aunt Joanna = piano (or just Joanna)

B

Baked Bean = queen
Ball of Chalk = walk
Band of Hope = soap
Barnaby Rudge = judge
Barnet = Barnet Fair = hair
Beezun = Bees and honey = money
Billy = Billy Bunter = punter (i.e. customer or mark)
Billy Hunt = cunt
Billy Lid = kid
Biscuit Drum or Crumb = Bum (Rear end, Buttocks)
Bluebottle = Bottle and stopper = Copper = Policeman.
Boat = Boat Race = face
Bob Hope = soap
Boracic (freq. contracted to brassic) = boracic lint = skint (i.e. penniless)
Brahms = Brahms and Liszt (classical composers) = pissed (i.e. drunk)
Brass Tacks = facts ("facks")
Bread = Bread and Honey = money
Bricks and Mortar = daughter
Bristol (or Bristols) = Bristol City (UK football club) = titty (i.e. breast)
Britney Spears = beers
Brown bread = dead
Bubble = Bubble and squeak = Greek
Butcher's = butcher's hook = look

C

Cain and Abel = table
Chalfonts = Chalfont St Giles = piles (i.e. haemorrhoids)
China = china plate = mate
Cock and Hen = ten
Creamed = cream crackered = knackered (i.e. exhausted or beaten)
Currant bun = sun or The Sun newspaper

D-E

Daisies = Daisy Roots = boots
Dame Judy = Judy Dench = stench
Dead 'orse = sauce, as in a dog's eye and dead 'orse = a meat pie and sauce
Derby Kell = Derby Kelly = belly (see Music Hall song Boiled beef and Carrots)
Desmond = Desmond Tutu = 2.2 (lower second class degree)
Dicky = dicky dirt = shirt
Dicky or Dickie = Dickie Bird = word = as in "not a dickie", or even "not a dickie bird"
Dog = dog and bone = phone
Dog's eye = pie, as in a "dog's eye and dead 'orse" = a meat pie and sauce
Donald Ducked = fucked (as in broken, not working)
Doris Day = Gay 
Duck and Dive = skive
Ducks and Geese = police ("pleece")
Duke of Kent = rent, also bent
Dukes = Duke[s] of York = fork, i.e. hand, now chiefly when balled into a fist
Dustbin Lid = kid
East and west = breast(s)
Eighty-sixed = nixed (as in kicked- or thrown-out) [American rhyming slang from the 1930s]
Elephants = Elephant's Trunk = Drunk

F-G

Farmers = Farmer Giles = piles (slang for haemorrhoids)
Fatboy Slim = gym
Fireman's Hose = nose
Flowery Dell = (prison) cell
Four-by = Four by Two (A common size of timber) = Jew
Fox = fox and weasel = diesel
Frog = frog & toad = road
Gay 'n' hearty = party
George Raft = draught
Germans = German bands = hands
Ginger = ginger beer = queer
Gregory = Gregory Peck = neck, or cheque
Grim 'n' gory = story
Gypsy's = Gypsy's kiss = piss

H-J

Half-inch = pinch (i.e. steal)
Half ounce of baccy (i.e. tobacco) = paki (Pakistani)
Hampsteads = Hampstead Heath = teeth
Hank = Hank Marvin (singer with Hank Marvin and the Drifters) = starvin'
Honky tonk = plonk (cheap wine)
Iron = Iron hoof = poof
Jack = Jack Jones = alone ("On my Jack" = "On my own")
Jack and Jill = restaurant bill or contraceptive pill, depending on context
Jack Horner = corner
Jam jar = car
Jam tart = heart
Jay Kay = Takeaway
Jimmy = Jimmy Riddle (unknown person, not the character killed during the Waco siege)= piddle or widdle (urinate)
Jekyll and Hyde = Snide
Joe Blakes = the shakes = experienced after a heavy night drinking
Joe Blake = a snake
Jugs = jugs of beer = ears

K-N

Khyber = Khyber Pass = arse
Kick and Prance = dance
Lady Godiva = fiver (i.e. five-pound note)
Leo = Leo Sayer = all dayer ("I'm on a Leo" - drinking all day at the pub)
Lionels = Lionel Blairs (English variety performer) = flares (as in flared trousers)
Loaf = loaf of bread = head ("use your loaf")
Loop the loop = soup ("nice cup of loop the loop").
Mickey Mouse(r) = Scouse(r) = person from Liverpool
Minces = mince pies = eyes
Mutton = Mutt and Jeff = deaf = named after Mutt and Jeff, two early 20th century comic strip characters
Nails 'n' screws = news
Nelson = Nelson Mandela = Stella (Stella Artois), a Belgian brand of lager
Nobbies = Nobby Stiles (English footballer) = piles (haemorrhoids)
North and South = mouth

O-P

Oily = Oily rag = fag (i.e. cigarette)
Old Jack Lang = slang
Old King Cole = dole
Optic = optic nerve = perv = to look, usually with a sexual nuance, or a pervert
Orchestras = orchestra stalls = balls ("A kick in the orchestras.") [Coincidentally, "orchi-" is also the Greek root meaning "testicle."]
Oxford = Oxford scholar = dollar (Five shillings in pre-decimal currency)
Peckham Rye = tie (i.e. necktie)
Pen and Ink = stink
Pete Tong = Wrong ("It's all gone Pete Tong")
Pigs ears = beers (Ale)
Plaster = Plaster of Paris = Aris = Aristotle = bottle = bottle and glass = arse  [a three-stage rhyme]
Plates = plates of meat = feet
Porky = pork pie = lie, e.g. "He's telling porkies!"
Pony = pony and trap = crap (note: Cockneys also use "pony" to mean 25 - hopefully the meaning is clear from the context)
Pride and joy = boy

R

Rabbit = rabbit and pork = talk, as in "She can rabbit on."
Raspberry = raspberry tart = fart (as in "blowing raspberry/ies" = sound made by blowing air between extended tongue and lips)
Richard = Richard the Third = turd (lump of faeces)
Rock 'n' roll = Dole
Rosie = Rosie Lee = tea e.g. "Have a cup of Rosie"
Round the houses = trousers
Rubbity = Rub-a-dub-dub (or just Rub-a-dub)= pub = public house
Ruby = Ruby Murray (popular singer in the 1950s born in Belfast) = curry

S

Salmon and Trout = snout
Saucepans = Saucepan lids = kids
Scooby Doo = clue, as in "Sorry mate, haven't got a Scooby Doo".
Septic (often "Seppo") = septic tank = Yank (slang for an American)
Sexton Blake = fake
Sherbet = Sherbet Dab (child's sweet with Licorice & Sherbet) = (taxi) cab
Sigourney = Sigourney Weaver = beaver (vagina)
Skin = skin and blister = sister
Sky = sky rocket = pocket
Stoke-on-Trent = bent (gay)
sweaty = sweaty sock = jock = Scottish person
Syrup = syrup of figs = wig(s)

T-V

Taters = Potatoes in the mould = cold (eg "Its bleedin' taters!")
Tea leaf = thief
The Sweeney = Sweeney Todd = Flying Squad, a special division of the Metropolitan Police; used as the title of TV series The Sweeney
Thrup'ny (threepenny) Bits = tits (breasts)  
Titfer = tit for tat = hat
Tod = Tod Sloane = own (as in "on your tod", meaning "alone")
Tom Dick or Tom and Dick = sick
Tom = Tomfoolery = jewlery (mispronunciation of "jewelry")
Treacle = treacle tart = heart or sweetheart
Trouble = trouble and strife = wife
Two-an =Two-and-eight = state (as in "He was in a right two-and-eight.")
Vera = Vera Lynn (famous British wartime singer)= gin, heroin

W-Z

Wally = Wally Grout = shout (buy a round of drinks), as in "It's your Wally." Also stout or snout depending on context
Whistle = whistle and flute = suit = as in "a nice whistle"
Winona Ryder = Cider
Source