AC1 was by easily my favorite of the four games to play.
AC2, ACB, and ACR were basically the same game with small features added. I don't see why anyone would buy AC2 and ACB instead of AC1 and AC2.
Because AC 2 and AC B are actually good stories and the gameplay is good. AC 1's gameplay is uncomfortable, choppy, stiff, whatever word you want to use, the setting is thoroughly bland and uncolorful, Altair is a horrible, dull, uninteresting character and there's nothing gravely important about the Desmond story in 1. Anything you need to know is already there in 2, the Templars/Abstergo are an evil organization trying to control people, the Assassin's are trying to stop them, they use a machine to allow you to live your ancestors lives, bleeding effect, piece of eden, yadda yadda yadda. You might as well just read a recap of AC 1 because you won't miss not playing the game.
Yeah, there was a huge jump from AC 1 to AC 2 in style, and there wasn't from AC 2 to Brotherhood and Revelations. I wonder why? Maybe it's because AC 1 was a broken system and AC 2 wasn't. You don't break your formula once you've found out what it's supposed to be.
Also, if anybody's interested, there's a Youtuber I found named FusionCap who's running an AC III playthrough on his channel, he got the game early. He uploads frequently, so if you're bored and want to spoil a bit of the game, or you won't be able to play the game because you're low on money right now, you can watch it now. I'm making my way through sequence 1 but I'm gonna stop when I get to sequence 2 because I don't want to just blow through everything and have nothing to do when it comes out. Looks really good, though.