I have been playing marathon for almost a year now, i met it through Halo, and i love it. I first played the entire trilogy on the iPad, though i couldn't exit Pfhoraphobia for some reason. Marathon 2 was the first one i completed. Marathon Infinity was even better then the previous two. I've played a couple of third party scenario's too, like Rubicon and TGI (my favorites) and siege of Nor'korh. And i've almost finished Phoenix.
I would like to make my own scenario one day too, i have some great imagination. I already downloaded Weland and i'm trying to make maps, though it's not much of a succes.
Anyway that's me, i hope i'l be a fun Pfhorum-visitor (not sure if that's the right term but i think you got what i meant right?)