If you upgraded from a trial account, you are missing the following:
Stygian Abyss: Gargoyle Race, Throwing, Mysticism, and Imbuing as well as access to Ter Mur and the Stygian Abyss Dungeon
High Seas: Access to the new larger ships and pirate hunting as well as fishing stuff which I'm totally unfamiliar with
Time of Legends: Access to Eodon as well as to Skill Masteries. Furthermore, each new publish seems to release new content in these lands which is where you'll find the bulk of the players these days as they enjoy the latest thing.
Rustic Theme: Rustic house tile set, a few rustic item that can be made by crafters, and the ability to place New Magincia vendors
Gothic Theme: Gothic house tile set, a few gothic items that can be made by crafters, and the ability to place New Magincia vendors
One of the Old Anniversary Editions (I forget exactly which one, I think the 8th year): Crystal and Shadow House Tile Set (You'd probably have to find an unopened copy of this through Amazon)
I think I got just about everything. Others can chime in and elaborate or if you have specific questions, I'll try and answer.