The tongue/finger but hole/amazing chest ones are really lame and uncreative. If you're going to leave dirty message at least be creative about it. They are so common that I've seen them a million times.
I liked the "man? woman?" one in front of that shaking carriage in the entrance of Aldia's Keep in DS2.
And in DS3, "Be wary of crab, time for bleeding" or something in front of a female NPC. lol, at least this one was creative.
"Don't give up, skeleton!" was funny the first time but also got a bit old.
"Oh, man!" before a difficult encounter in Bloodborne.
Fatty jokes. "Try jog, fatty" in front of a narrow opening the character can't go through.
Wheelchair jokes. Also got old, but the first times, I admit I laughed and they aren't as ubiquitous as "tongue but hole".
"Dwarf required ahead" for small openings near the ground.
"guts?" in front of the greatsword loot in Dark Souls 3.
(I also rate up most useful messages, but it's always the silly ones that get more ratings it seems.

)
"Lever ahead" placed directly in front of a lever.
Haha, that one actually helped me once. For some reason my eyes glazed over and I missed the lever so the message made me go "huh... that's right! Thanks!". xD
Haha perfect! I think I saw a similar one.
I always laugh at "pitiful really"
I love seeing those after finding a big chest with... Tomb Mold.