Jessie himself seems to not give himself enough PR, so here goes.
With epic voice acting and great humor, Jessie Cox does awesome commenting and even requests in the Cataclysm beta. And in all honesty, does not get enough attention.
The Wrath of Hogger!
http://www.youtube.com/watch?v=OI2f4nC9tKc
Punching Deathwing in the face!
http://www.youtube.com/watch?v=M4VcMKK-ZR4
Jessie shows misc things due to requests, such as Southshore and EPL. Also showing off a new branch of the Argent Dawn that are like a middle-ground between AD and the Scarlet Crusade, so some new and interesting lore in here, worth watching!
http://www.youtube.com/watch?v=WA_xj7drn04
The entire Silverpine quest-chain leading up to the shooting of Sylvannas.
http://www.youtube.com/watch?v=OuBw7XXemy4
The new Worgen faces. The old ones are in there too! So they seem to stay.
http://www.youtube.com/watch?v=Zm5mO8Wb1RU
Those are just a handfull of all the other videos. Now go see them! And thanks Jessie for giving a much nicer alternative of videos as opposed to others and great humor.