I just started my first Monarch game a couple days ago. Going pretty good. I havent discovered all the other civs yet but on my continent I'm number 1.
Once I got the hang of expansion and micromanagement, Regent turned out really easy. I won two Regent games and decided to step it up. Now my first monarch game is turning pretty successful, though I'm about to hit that slow research point known as the early middle ages.
I'm thinking about dropping my science to 0% and seeing where that takes me. I've tried it once before but it didnt work out so well on the lower levels. It'll be a good expirament for me.
It's awesome to see how much my game has grown. My friend and I started playing Civ a few years back. He stopped and kept on going. I got serious on Civ about four or five months ago just when he began playing again, but he is somewhat less than a "fanatic" and thus he still plays on Chieften instead of accepting the challenge of higher levels. Anyway I look at his games a lot and can just spot errors like mad, much as the Diety and Sid players here could spot my errors easily. I use him as a comparrison to how much I've matured in this game.
I've yet to try a OCC. Maybe after I win monarch
EDIT: BTW. My first monarch game was played totally random. I ended up getting what looks to be a pretty average world, probably temperate, 4 billion, and continents. I ended up with the American's though. Not sure how to cope with that late Golden Age. I figure the game will be over without me ever having hit it.