What?
I submit to the court Exhibit A: THAC0
I rest my case, your Honor.
THAC0 was pretty easy to wrap my mind around. A bit convoluted in retrospect, but I never thought of it as such back then.
I had more trouble accepting the idea of 1-minute rounds, though. And 2nd ed's bizarre take on the True Neutral alignment pretty much only made sense within the Planescape setting, and then only barely.
Personally, I wouldn't go as far as saying 2nd edition was the best edition, but it's definitely the one I've played the most. As such, it's the source of many fond memories, more than any other edition is.
I never played 4th edition, actually. I remember being turned off it even before the full release. They released a sneak peek of the rules shortly before (which they demanded full money for - a little arrogant, if you ask me). I read the back cover of it, which was basically a bragging list about the numbers of monsters, character classes, fancy moves, pretty items and so on this new edition would bring to people's gaming tables.
And right at the bottom, it said: "And for those of you who like to roleplay - we haven't forgotten about you, either."
Yes. Yes, you obviously have. "Those of you who like to roleplay". Sheesh.
I put that one back on the shelf. 4th ed never interested me after that.
Mmm...Planescape...