Initiative is one of my favourite subjects to discuss in regards to rpg (combat) mechanics. I posted a few times recently about "old-school" initiative, mainly about how people playin oD&D and B/X usually use it, 1d6 simple roll, simultaneous actions all that.
The link above on the other hand, shows the other side of the coin, what initiative had become in AD&D as the game grew increasingly complex. It is a "cheat sheet" (20! pages long) compiled by David M. Prata, explaining how to determine initiative.
Just by looking at it I can see about a million instances where you could simplify the mechanics without losing any of the complexity. Ah the halycon days. Love it.