does anyone even look at forum stickies anymore? :laugh:
Anyway,while the link Pio gave above links to the main modforum, to give you a better view of your choices:
The Master Mod list
The 8 major overhauls are what you want to take a gander at. Personally, the top four are
Game of Thrones (you probably already know what this is about)
CK2Plus (a balance of balance, events, and mechanics changes)
Prince and Thane (basically focuses on flavour and events with a lot of balance)
Balansegang (focuses on balance without adding too much)
While I personally prefer Prince and Thane, CK2Plus has the advantage of being compatible with Magnate Lords (which focuses on economy) so it wins for now. Granted, they keep getting updated regularly so you might want to read the last few thread pages of each to get a feeling when the latest stable version is coming out to avoid the frustration of losing a day's progress only to be assaulted by the temptation of a new version that would make your current playthrough incompatible

.
Of course, there are occasionally a few mods that haven't made it into the master list yet (mostly either because they're still in alpha like Dawn of Kingdoms, or because they're too... frilly, like the beloved
Kingdom of Gensokyo touhou mod :laugh: [which needs more love and mouth-to-mouth btw so clickity clickity

])