Hi i'm new and have a question please reply

I have had guild wars for ages now but never played it...dont ask why lol but i am finally gonna start. So here is my question, i only have the standard GW not factions or nightfall etc, do people still play standard GW or do i need Factions when i reach level 20 or nightfall...basically what are the factions and nightfall? are they just expansions that i can wait for? or do i them now?
Thanks for all ya help and oh yeah...hello i'm new

Prophecies (GW original) still has plent of people in it...although during the US daytime hours not that many. But the evenings are usually better. U don't need factions or Nightfall*not released yet* to play or will never need them if u don't want them as they are "expansion/stand alone games. Although when oct 27th gets here both prophecies and factions may seem a little empty due to the release of NF. oh yeah....Welcome to the game

hey Dynodevil, welcome to the forums.
Its my opinion that having 'just' the plain old GW chapter 1 is perfect! I would not buy either of the others until you've at least played a significant amount in the one you already have and decided if you even like the game
There are a lot of reviews out on Factions, and soon will be as well for Nightfall, get one or both of those later if you enjoy Prophecies.

Prophecies is a great game.
Factions is great in its own way. If it were first, I dont believe GW would be as popular as it is.
Nightfall will take the good parts from the previous two and build on them to make something better than both.

Ok cool thanks guys i'm from the Uk and if anyone wants to be my friend just add me...also lookin for a guild hehe thanks again guys and gals