I know what you mean, but I think there's a lot of potential from the other side of things, too.
Berserk showed some of the best bonds and betrayal that I've ever seen in any medium, and nothing has really topped it.
*SPOILERS START*
Guts was a mercenary who had nothing to really lived for, so all he did was go from battle to battle, taking life-threatening risks until he was finally killed. His show of strength caught the eye of Griffith, who ran the Band of the Hawk. After a shaky start, Guts is pretty much overpowered and agrees to the Band at Griffith's desire. During Guts' time in the Band, he finds respect and friendship in his colleagues, especially Griffith, who wishes to go from common mercenary to a king, regardless of the caste system in place. Guts admires Griffith's lofty goals, and vows to fight for him, to make his dream come true. However, we start to see more of Griffith's seedier side, showing that he really is willing to do anything to achieve his goal (and I do mean anything, like laying with a king in order to gain his favor). When Guts asks Griffith to take out a lord standing in his way, Guts accepts, but ends up also killing the lord's innocent son. This causes a rift between them, and Guts leaves the Band of the Hawk.
While Guts is gone, Griffith is imprisoned and tortured relentlessly for having started a relationship with a princess, which the king didn't like, Griffith still being thought of nothing more than a lowly mercenary. Guts finally comes back at the behest of his love interest, Casca, and a few of the Band concerned for Griffith, and they go on a rescue mission. Griffith is mentally broken and physically weak by this point, and Guts and his friends try their hardest to escape with Giffith from the king's men. Having escaped and laying low, a supernatural eclipse begins, and pulls the Band of the Hawk into a demonic dimension. Griffith, in possession of a strange necklace referred to as the "Egg of the King" is offered a spot within the God Hand, a group of powerful demons. Griffith accepts this power as another means to become a king, and in the process of gaining that power, he sacrifices the whole of the Band of the Hawk to be devoured by demons. Guts attempts to save his fellow bandmen to no avail, and when Griffith is reborn as Fempto, Guts is pinned down by a demon, while another clamps down on his arm. Guts is forced to watch Femto rape Casca into insanity, while Guts himself is hacking his own arm off with a broken sword.
Guts and Casca are saved by the Skull Knight, who frees them from the Eclipse, but demons now permeate the world, and Guts tries to protect himself and the now mentally-simplified Casca from the demons that constantly hunt them, because they bear the brand. Femto continues his exploits to become a king, and cares little that he sacrificed so much to get where he was. He sacrificed not only the Band of the Hawk, who trusted him with their lives, but also Guts, who he gave a purpose in life, and who shared in his ideals.
*SPOILERS OVER*
I'm paraphrasing and glossing over quite a lot, but Berserk is one of the best series to see the ideals, bonds, and betrayal. This is really for anyone who was interested, not just you Meg5493, since I mentioned Berserk. I highly recommend taking a peek at it.
