This thread can become a classic if everyone keeps going. Can it be BTTT?
The trick is sticking with GREAT doctored photos - fakes which impacted society to a non-trivial degree.
#6 caused a brief stir in international news, depicting a captured US soldier until someone pointed out the photo was of a toy.
#9 provided circumstantial evidence that something is wrong with the Obama’s eligibility for President (why post a lame fake as proof of eligibility when the real thing would resolve the issue in minutes for a few dollars?).
#10 ended Dan Rather’s long career as top news spokesman.
#11 was the first great “photoshop job”. Obvious fake/funny, but showed how a very convincing fake could be made in minutes.
#28 was allegedly found in the 9/11 WTC rubble and was a sentimental news hit - until proven a fake.
#30 became one of the great modern Internet fads.
Others above are notable for being outrageous for gall to fake & publish so publicly, but did not have quite the resounding cultural impact.