Puns and sight gags. It’s the two lowest forms of humor all rapped up in a jpeg! I’m not talking about any old funny captioned snapshot. No, there has to be an awful pun involved or else it’s just a picture with words. I’ll share my two favorites and, if you please, will link to some too, yes?
This one always gets a chuckle.
I got this one from Straight Dope Land and will send it out when anyone aks for photog tips.
These are all awesome! Or, alternatively. 
I don’t know if thesequalify, but I love them. The last one on the bottom I saw out of context and took a while to get.