Vanguard: Saga of Heroes - If it was released in the state its in now, it would be unstoppable.
Yes, this game was released with a rocky start. There were bugs everywhere and some people couldn't even play! It gave the game a bad reputation and now people are unwilling to give it another chance. If you are like this, please rethink it. You can pick the game up for a cheap price anyways now, so you might as well take advantage of it and try out the free month.
World - The world, Telon, in VG:SOH is huge. Absolutely, unbelievably huge. The world is ALSO seamless. It is comprised of 'chunks', and if your computer is decent enough it will barely notice when you cross a chunk. Lower end computers may notice it, however they are constantly increasing new patches and bug fixes, along with hitching fixes.
Lore - This game has a lot of lore, however it isn't apparent on the surface. You must read the quest logs, and most importantly, take part in Diplomacy. You can change the world with diplomacy, which brings me to the next point.
Separate "Spheres" - There are different areas of the game, classified as "spheres". Adventuring, Crafting, Gathering, and Diplomacy. Each sphere is completely separate from the other, such as if you want, you can level Smithing to 50 and be level 1 in Diplomacy or Adventuring, or vice versa.
Diplomacy - It is basically a minigame within a game that serves a purpose. You can use it to make money, get gear, mounts etc. Its a lot of fun too.
Adventuring - Just like any MMO, choose a class and level it up. Raid and stuff.
Crafting/Gathering - Level up a trade to make armor/weapons, ships, houses etc. Gathering by cutting down trees (they actually fall and shake the ground), mining etc.
Transportation -
Sailing - Build/buy ships and sail the world. A form of transportation.
Flying Mounts - Just as it sounds, rent one at any level for 5 minutes or be a high level and get your own.
Horse - Level 10 you get your first horse. It is upgradeable/trainable.
Racial mount - at 30 get your racial mount.
Riftway - Instant teleport to certain locations in the world for a fee.
There is much much more to this game, so be sure to check out http://www.vgwalkthroughs.com/page/guides/4 video. It is really good. Also check out http://www.youtube.com/GTVolition for some videos of certain locations.
Please give the game a try, it is definitely worth it.