I was very excited to see the American Reunion movie. I saw American Pie just after college and remembered it was quite funny.
Jim, Michelle, Oz, Heather, Stifler reunite for their high school...
D20 Modern's very poor. If you want a modern-day system, there are lots of better alternatives, though Savage Worlds is the closest (and cheapest). Also consider Unknown Armies, or the vanilla World of Darkness book.
I've heard good things of AFMBE, for what that's worth.
I haven't played D20 Modern, mostly because it struck me as an attempt to do Shadowrun without the cyberpunk elements, and if you want to do that, just play Shadowrun without the cyberpunk elements.
As for All Flesh, I've read the basic rule book and it seems pretty solid, and there's a ton of sourcebooks out there to take the game to different settings, including pirates and Westerns.