More of a spoken one, but here goes -
Q: What’s so great about fucking 25-year-olds?
A: There’re twenty of 'em!
Say it out loud if you don’t get it.
Joe
I think the problem is the usage of the phrase “coming on a treat.” With my mighty reasoning power, I’m guessing it means something like “coming along great.” Americans (like me) have never heard the phrase “coming on a treat.” But the American phrase has no double entendre possibilities.
Joe
A man and a young boy are walking into the woods at night. The boy says, “I’m scared”, the man says, “You’re scared? I have to walk back alone”.
What’s the smartest thing that ever came out of a woman’s mouth?
Einstein’s cock.
What’s the worst thing about sex with a four-year-old?
Getting the blood out of the clown suit.
What do you call a short-legged Mexican woman?
Consuelo.
Why did Helen Keller wear tight pants?
So you could read her lips.
Why do women have cunts?
So men will talk to them.
What do you call a quadriplegic lying in a leaf pile?
Russel.
OMG! My eyes are offended just reading that.
We have a winner!!
What do you call a quadriplegic learning to water ski?
Skip
I guess this is the safest place for racist jokes.
A white guy and a black guy were walking by a river and they quickly striped off to get ready to swim. The white guy said “slow down! it might be too cold, let me check”, and he promptly dipped his penis in to test it “it’s warm, let’s dive in”. But the black man quickly interjected “Hey, safety first, I’ll check how deep it is”, after “testing it”, he said, “all clear, it’s only two feet deep”
Another racist one.
Why do black people eat chocolate so carefully…
because they are afraid of biting their fingers
A black man walks into a bar with a parrot on his head.
The bartender walks over and says “that’s pretty cool,where did you get it?”
The parrot says “Africa they’re all over the fucking place”
Why was Helen Keller such a bad driver?
She was a woman
Still, my favorite offensive joke is best without a punchline. And yes I got this from The Simpsons, wherein Krusty begins:
“This guy walks into a bar, he takes out a tiny piano, and a twelve inch pianist”
“oh, no, wait, I can’t tell that one!”
LOL
There are a few punchlines for that one floating around. But it really is best without. Imagination and all, I mean. 
Reminds me of our seventh grade camping trip, when our strait-laced English teacher told us, “There once was a man from Nantucket… well, I’m afraid I’m just going to have to leave it at that.”
Nowadays, of course, kids would look it up on their I-phones and the mystery would be solved in minutes, even out in the woods. No such luck for us kids back in the day.
The “r word” usually makes me stabby, but that’s too funny to get worked up about. (it’s also true BTW)
Ha! That one’s brilliant 
Q: Why do all men float?
Y'know, like if I throw them in the lake, they float to the top?
(C'mon ladies, I know you know the answer!)
A: Because they’re all scum!
Q: Why are only 20% of the people in heaven women?
A: Otherwise it’d be just like hell!
A few more [ul]
[li] “Jesus loves you.” A nice gesture in church.[/li]
A terrible thing to hear in a Mexican prison.
[li] “Darling, why are there broken condoms on our couch?”[/li]
“Stelios…
Would you please call our children by their names?”
[li] I was driving around the other day and started feeling really horny. So I decided to swing by this well known dogging spot that was close by. There were a few other cars there so I pulled up and joined in.[/li]
I had a great time, but I think I failed my driving test.
[li] When my girlfriend said she was leaving because of my obsession with The Monkees, I thought she was joking.[/li]
And then I saw her face.
[li] I’m Josef Fritzl, and no windows was my idea![/li][li] Little Johnny walks into his parents bedroom to find his Dad giving his Mum one. His Dad smirks and throws a pillow at the door saying, “Get outta here, you little shit!”[/li]
A couple of hours later Dad hears a whole lot of commotion coming from little Johnny’s bedroom. He goes up to find little Johnny giving his Grandma a right royal seeing to.
Little Johnny smiles, “It’s not so fucking funny when it’s YOUR mum, is it?” [/ul]