Although I didn't discover them, water ladders and cart boosters were so much fun. That feeling of almost cheating, using the bugs in the system to do magic things was so much fun.
I'd definitely credit Minecraft for rekindling some love for hacking, in the classic, non crack sense, but, matrix like, bending the rules to do NEAT stuff.
Then mods, pipes and auto crafting, bigger stuff.
I remember when tool damage was introduced. I was annoyed, but it was ok. I think around the time of food/hunger it started losing its luster. grow potatoes or butcher cows and pigs. it was ok. But that's the time I started drifting away.
Just an amazing game that brought me joy. good stuff.