Bought Nightfall yesterday, made a Dervish...yeah, it's a great class. Similar to Assassin in that it takes a bit of work to do well, but if you layer your enchantments right you can basically act as a tank (two of the first ones you get work great - one boosts up your HP a ton and the other boosts your damage, I always have them active). Which is cool. And then I went with Monk as my secondary.
The original (now called Prophecies) was European, then the Asian one was Factions. Then Nightfall- which was actually a bit broader than Egypt, having a big Persian area too.
That was the point where they abandoned the stand alone model when they decided that the game was going to bloat too much so they needed to make GW2 (still no sign). So to tie up things in the world they released the 'Eye of the North' expansion, which although an expansion for all three campaigns takes place in the frozen north areas of the original European-style setting (though it also added stuff like dungeons to the game).