The newest Guild Wars: Nightfall...
The campaign:
Normally i dont PvE cause i just dont like it, but this time they make a big leap forward. With a interactive story based on some of your decisions and a interresting story Guild Wars is finally heading in the right direction PvE wise. The campaign lasts pretty long, cant give you exact hours since im have not even finished it yet, but have enough experience to say: The PvE is finally worth playing.
The game introduces 2 new classes which are already implemented in many many GvG (guild vs guild, a player vs player battle) builds and seem quite effective. The 2 classes are really unique in the GW (Guild Wars) universe and play very differently from the existing professions (or classes).
With the expansion (actually a standalone game) you get another set of 350-ish skills for the 8 already existing professions, giving lots of new options for players doing both PvE and PvP.
The graphics have gotten a update aswell, though it's not something really special... it's still... Guild Wars! Which is a good thing in my opinion.
There arent that many bugs yet, but there are some imbalances in skills. Unfortunaly, Arenanet decided to launch a tournament (fun season) right after the launch, this means they cant "just balance skills" because that would be unfair for a lot of guilds that are doing good now.
The sound is a good as always nothing to complain about.
The value of this game is absolutely great, you can play through PvE with 10 different professions that play totally different and experience a different story. After PvE there is still PvP, they added Hero battles this time which are 1on1 battles that include the Heroes that you get during PvE (so it's 4v4, 1 player and 3 controlable "henchmen"), this is very challanging and fun to do. The same goes for the already existing PvP, random arena's, team arena's, Hall of Heroes (Heroes Ascent) and GvG are all heavily influenced by this chapter and all in a good way.
Conclusion:
If you already play GW, then Nightfall is a no-brainer... i think it's the best saga to date (that doesnt mean a higher rating, since graphics are the same etc). If you havent played GW yet, it might be a strange game to get into, because (like factions) the start is pretty fast (though slower then factions). If you really want to enjoy GW to it's maximum, you should start to play Prophecies (GW original campaign) and Nightfall. Factions is also a great title, but not as engaging as Prophecies and Nightfall and had less of an impact on the overall game.