Adult Swim has made all episodes of Samurai Jack from Season 1 to 5 available on their website, and FREE TO WATCH!
Here’s the caveat: the free streaming is restricted to US only IP addresses. So if you live outside the US, you can use your preferred VPN and set it up for US access.
For those who are new to or have not seen Samurai Jack yet, here is a quick summary, taken from Wikipedia:
Samurai Jack is an American action-adventure animated television series created by Genndy Tartakovsky for Cartoon Network. The titular character, “Jack,” an unnamed[a 1] Japanese samurai who, after nearly defeating the ultimate evil being known as Aku, using a magic katana capable of cutting through virtually anything, is sent forward in time by him to a dystopian future ruled by the tyrannical shape-shifting demon. Jack, who is brought to the future with only his robe, sandals, and sword, quests to travel back to his own time and defeat Aku before he can take over the world. Jack’s search for a way back to his own time period transcends Aku’s control, but Jack’s efforts are largely in vain due to the ways back to his home being just out of his reach.
You can also check out this video summary: