At high risk of being incredibly insensitive, how long before we see the t-shirt:
“I survived the attack on the World Trade Center, and all I got was this lousy t-shirt”
“Hot enough for ya? Heh heh!” - said by stupid people to innocent passersby on hot days. Not funny then, not funny now.
When I was a kid the dentist had all sorts of stupid posters like “Hang In There” on the ceiling, so while they were hacking at your gums with a meat hook you could look up and see a funny chimp with a banana and be completely distracted. Well, maybe not completely…
And this is a personal one, but my last name is McDonald. It ceased being clever to ask if my father was named Ronald. I’m mystified each time someone says that to me. I’m 27 years old, do you actually think you’re the first (or even the fifteenth) person to think of the blindingly clever idea of putting “Ronald” with “McDonald”? No, no you are not clever, and no, it is NOT fucking hot enough for me.
I want BLISTERS.
On the bumper sticker note: “My other car is a ______” is pretty damn played out, but the other day a friend mentioned “My other ride is your daughter”. Gotta be the only one that has made me laugh for a while 
I can think of one instance in which it WOULD be funny.
Imagine seeing an Astin Martin, A Rolls Royce, Or similiar
hundred thousand and up priced car. As it pulls away,affixed to a bumper that cost more than your whole car, you spot this sticker “My Other Car Is A Porsche”
BTW McDonald, you have my sympathies. My first name is Spencer. No, I am not for hire. No I do not have a lot of gifts. No, the store does not give me a discount. No, these jokes weren’t funny in third grade either.
Along the same lines as this… My wife’s name before we were married was Dawn Epstein. She grew up in the 70’s. She heard all of the Helen Reddy “Delta Dawn” jokes, AND the Welcome Back Kotter “Juan Epstein” jokes.
DumbAss example number 2:
I used to be a ‘beer man’ at the Texas Rangers’ games. Sometimes I’d want to say “ha ha real fucking funny” when I would pass a beer down a row, and people would act like they were going to keep it, or when they were passing someone elses money to me, they would say “keep the change” or act like they were going to put it in their own pocket. Sheesh!
Dumb Asses can be so predictable!
E3
Spartacus, there was a great Far Side about this one, with three generals standing around a planning table. One of them is wondering, “What if we gave a war and everybody came?”