Yugioh, take a shot of alcohol everytime we mention friendship.
(Not if you have to drive)
Warning references to Yugioh Abridged by Little Kuriboh ahead, so sorry if I offended you.

I think everyone admits that season 1 was random, yes Exodia was pretty cool, plus the  friendship symbol, wow that must show their friendship being strong, even stronger than the actual card called Symbol of friendship.
"oooh Kaiba boy~" Pegasus oowed
"What are you gay?" Kaiba glared at Pegasus. "Bitch I might be" Pegasus smirked at Kaiba

Season II: Still random but you can expect that, I like the duel disk design and idea, the god's, Silfer, Obelisk and Ra was incredible. (In one of my first packs I think, I pulled Silfer, twice)

Season III: Deck master rule was pretty cool, most interesting I think was Duke, Tristan, Serenity vs Nezbitt, Yugi and Joey vs Big 5, Kaiba vs Gozaborzo. It was all pretty cool, the battles between Yami Marik vs Joey and Yugi vs Kaiba, finally Marik vs Yugi and Kaiba vs Joey, but it was their friendship that saves them

Season IV: I was personally hyped for this season, the three dragons/knights of atlantis were cool. Why so much hate (besides them acting like children sometimes, but hey, it's suppose to be about children, showing them the many adventures of friendship). (Yes series 1 that is in English dub. )

Season V: well split into three small seasons.
Capsule Monster: aka rip off of pokemon/digimon. Skill kinda cool about it.
Grand championship: yeah some things wrong with this, like Vivian, I have no hate against female characters but she played like a nine year old, everyone probably remembers only Dragon Lady, which can be pretty powerful, Siegfried's and Kaiba's rivalry, meh, why Valkyrie's even, yes to destroy Kaiba's dragons. Why didn't they name it Dragons vs Goddesses (yes would cause some ruskes.) Leon's deck is kinda interesting, bases around fairy tales.
Return to Egypt: It was pretty cool showing Atem as the Pharaoh, Zorc was kinda climactic but everyone (well hero always wins now in the end), knew Atem was going to win. Finally Yugi (little Yugi) gets to duel!Best part ever would be both going against each other, showing how much bonding and friendship they had.

Well that was fun.
Favorite monster?
Character?
Not really sure, Blue Eyes, Red Eyes, Silfer, Valkyrion, and Dark magician.

Say anyone want to hear a friendship speech?