1 GX anime/manga
Although some say it was terrible I loved a good majority of the gx anime especially season 4, where you see a much darker but mature Jaden. The manga was amazing as well. It placed a new spin on things and Jaden used the real elemental heroes. The characters were also placed in a much better light ex: chazz and baston.
I dont know why you think so Lelouch, but 5ds is considered the best of all the yugioh animes for most yugioh fans. The idea for the series was speed and the charters were well distributed from kind and caring to serious. I have no idea if you watched subbed or dubbed but 5ds is my second place for the yugioh series.
What else is there to say? This was my childhood, and I loved it to death. So why is it at three? I can barely remember it and I dont have time to rewatch it sooo yeah... I guess that's why.
I could not get past the first 3 episodes so maybe it got better....maybe. Most fans agree this was the worst.
? Arc 5
I have heard amazing amounts of praise for this. If you get past the idea of the main character riding a panda (which is pretty weird) it is supposed to get better. Some say it is second right under 5ds beating all other series, I guess I will find out.
0. Yugioh season 0
I don't really consider this yugioh as the card game is mentioned/played twice in passing in the manga and a few more times in the anime. I do however find it amazing. Yugi and yami are like two sides of a coin. Calm and gentle, to ruthless and cruel. To be fair the puzzle did not give yugi dueling skills but "dueling" aka gambling skills. I have to admit Yami is one hell of a character in this. Pretty sure he kills at least 3-4 people and ruins the lives of countless others. This is also where Usio from yugioh 5ds appears and was later recycled into 5ds.