I agree about enjoying the variety of games seen in the early manga. A core memory of mine from way back in 2002 was being a little kid picking up volume 3 of the manga -- first time I had ever held manga in my hands before -- and seeing things like Yugi and Mokuba playing Capsule Monster Chess, or the digital pet chapter where they're basically playing with Tamagotchi. And who can forget the criminally underused Dungeon Dice Monsters? That was a really cool concept for a board game.
Personally, my favorite part of the early manga is the Monster World arc introducing Bakura. Those chapters were the inspiration that pushed me to start working on my own tabletop RPG, something I'm still toying with to this day. To say that Takahashi's work was influential on myself and my interests and values would be an understatement.