Mine is pretty strange because it's not quite English, but it's not quite Welsh. It's known a Wenglish, or talking bollocks, take your pick. It contains some rather obscure grammar as well.
Butt= Mate
George= Anyone. I know a lot of people named George...
Score= 20 pounds
Oner/ton= 100 pounds
Shiner= A women who sucks lots of cock. Get it, spit shine...
Dap it= run away
Bewt= Someone is an idiot.
Clart= Used by chavs to call each other mate. Mostly used to call someone a chav, as in "he's a propa claaarrrt!"
Aye= Yes
Aye-aye= Hello
Ta= Thank you
Cwtch= Cuddle or hug.
Hahaha this is epic, I've just been looking into my accent and our slang. It's unbelievable how different we speak from proper English.