I have seen a lot of YouTube videos since I got broadband access. Among those that are both funny and have to do with history, here are my favorites.
First, Medieval Helpdesk: In this funny Norwegian language video, a monk gets help to use his first book!
That Mitchell & Webb Look (A British Comedy Duo)
The reluctant Nazi ("Are we the baddies?").
Renaissance computer expert.
Explorers (how places got their names).
A new fuhrer, or what really happened when Karl Doenitz succeeded Adolf Hitler.
This British educational/comedy program is the best source on this list, inasmuch as it is based on a series of funny history books.
The Aztec priests song.
King Pepi II's super sticky anti-fly honey slave.
Mullions XP (the founding of the Church of England).
Stupid Deaths: Franz Reichelt (He should have received a Darwin Award!).
Stupid Deaths: The Grim Reaper Quits.
The Pharaoh Report.
The Viking Payoff (What if Ethelred the Unready had today's technology?).
Ruthless Rulers: The English Kings and Queens Song.
The Roman Report with Bob Hale.
Richard III's Song.
Nasty Knights: Castle Defenses.
The War of 1812: The Movie. (Now you'll know what it was all about!)
Soviet break dancing, from the bad old days of the Cold War. The music is from the '80s band Run DMC, of course. I wonder why the USSR didn't show this video to the world; it could have been a minor propaganda victory for them!