Things Intended to Be Funny, That Aren't.

Clowns
The boys and I popped into Ikea for a meat-ball based lunch and found, to our utter disinterest, that it was a family day. That's why there was a torn-faced clown wandering around spinning plates. Clearly bored riged, he tried to strike up conversation. The topic? Our local undertaker. 
Top Gear
Three grown men acting like teenagers as they read out lines from clunky script. There are cars. 

Burniston
Shell suits and shouting isn't enough to constitute Scottish sketch comedy. Or, in fact, sketch comedy from anywhere.

Everything else

'Funny' slogans. You don't have to be mad to live here, but it helps. No it doesn't. 
Putting a hand out to shake then taking it away. Rubbish. Never funny.
See-you-Jimmy hats, fake tits.
Real tits. Especially to the person who owns them.
Women pulling up men's kilts.
Most photoshopped pictures
Most sit-coms. Should be called sit not-coms.
Politicians' jokes. 
Posters (cards/mugs/keyrings/printed knickers) that begin Keep calm and...
Vic Reeves.
Anything that is introduced by: "You'll love this, it's hilarious..."