[Before reading my post, do NOT highlight the spoilers I've included, at all, until you've played through about halfway into Assassin's Creed 2. I would hate it if someone spoiled some of those things before I experienced them myself.]
Matt, Peach is spot-on with her advice. You really can skip the first game. The second game does a good job of explaining the
Spoiler:
"DNA" Matrix-style experience you have in Altair's past.
making it as though you didn't even need to play the first one.
The second one does better in just about every category: better story, better action, better climbing, less glitchy in combat, more fighting options, more weapons, funner upgrade system, a "Sim City" upgrade side option that I found quite fun to do, and some nice humor.
For instance, when you first meet
Spoiler:
your uncle, Mario, he says, "Itsa me!!! Mario!"
which made me lol pretty hard. I'm glad no one here on KMC ruined that joke for me because it made it much more fun. I also did not enjoy the "clunky" and slowness of AC 1 so I took Peach's advise (which she gave a long time ago) and just stopped and picked up 2. I have not played 3, yet. I plan to do so after beating Fable III. 🙂
Major Spoiler, do not highlight until you've beaten AC:2
Spoiler:
You should also love the crap out of the back-back story of AC:2 because of your distaste of religion. The story of Adam and Eve is explained and it's quite clear that they were not "divine" beings made by God and their "legend" got taken way out of context and morphed as most ancient stories do. It talks about the origins of man and I must say...AC:2 had such an awesome lore to it that I was truly entertained by a video game's story for the first time in many years. It was that good.