Now these videos are what I call ultra-spoilers, being that they are just the class story line for various classes. They effectively spoil everything about playing that class, well apart from side quests, but the main thing for a class is the cool class quest.
So why view them? They do show that certain classes have better quests than others for sure, and might give a flavour for the sort of play that a certain class has. For example, after watching these the Imperial Agent looks awesome, and the Sith Warrior class quests are just totally great.
Sith Warrior (female) quest up to the end of the starter planet:
Play list for the Sith Warrior class quests.
Play list for all parts
OMfGeeks have posted up a video they keep up to date with all the class story line videos:
Trooper play list.
Imperial Agent play list
Smuggler play list