I finished Halo 3 a couple of hours ago...

[LG[Infinite]]

It's nice to see the community take a firm stance against abusive language. As for Halo 1 and 2... you're not likely to find those in stores anymore. If you liked Halo 3, definitely get them. They're not only fun, but they'll give you a nice perspective of how the game has changed over time. It's kind of like how playing Mario64 then Galaxy makes it easier to appreciate both.