Which Version To Buy?

Hello, I just joined these forums and i've recently become interested in guild wars and thinking about buying it. I've been reading what other people have posted about the different versions but i'm still not sure which one I should buy. Prophecies seems like it would be the best but just because its the first version of the game. It seems like factions and nightfall wouldn't be as big as prophecies but i'm probably wrong. I have also been told prophecies had the assasin class but I though only factions had that. Please help me decide as I really want to play this game as it sounds really great.

NF is probably the most easiest in terms of having AI (heroes) that you can customize, having many tutorials to become familiar with pvp, small things such as dye preview so you don't waste any, and ability to change attribute points easily. Its also the most fun chapter imo. For now thats where most people are at, whereas the other two chapters have a smaller player base, at least for now.

You can only get the assassin and ritualist from factions as well as the prophecies characters.
You can only get the Dervish and Paragon from Nightfall as well as the prophecies characters.
Propechies you can get the Necro, Monk, Warrior, Elementalist, Mesmer, Ranger.
If you have all 3 and the accounts are joined, then the characters no matter from which game, can travel between the maps.

My advice would be to start with prophecies, it takes awhile to complete, although if you like the game as i'm sure you will, then aim for all 3.

I started with prophecies and enjoyed the game thoroughly, then i bought factions and would'nt want to play prophecies without the factions add ons, like material storage, being able to get the max armour from kaineng (Factions city) rather than Droknars forge (Proph city) which is harder to get to.
Now i have bought nightfall and would'nt want to play either factions or prophecies without it, because the heroes have helped with factions missions.

Each game compliments the other, hope this helps you make your decision.

thanks guys, i think im going to buy prophecies because im cheap and at walmart it says you can buy it for $35 so if i find it cheap ill buy it.