D***! You beat me too it. Dash_rendar, you've obviously never played this game; a billion kills can be racked up within roughly an hour of play, partially because populations are measured in the millions, and each turn equates to a full year; a full year's worth of orbital bombardment from 1,000 small capital ships (total weight of maybe 700 kilotons) can quickly reduce a full planet (up to 400 million, strangely enough) to a smoldering heap. I like to think of one of the plot sections from Descent Freespace: The Great War, hours after the destruction of the Vasudan homeworld. (8 billion killed, but by the enemy; the video clip of the bombardment looks amazing, though)
I must agree, MOO1 is by far the best game for raking up kills. I always playe as the cat-like MrrShans; they get a 40% accuracy bonus to starship combat, get +4 to their initiative, and develop weapons technology 66% faster than anyone else. At that rate, I have my fleets of doom (at least 100 ships equiped with weaponry good enough to penetrate planetary shields) by mabye the 80-100th turn, (I expand very agressively) and from then on, I raze a full planet at least every turn; since I usually play on the maximum galaxy size (108 planets), I'd say that a single game (which might last 8-10 hours, spanning mabye 3-4 days) gets me arround 10 billion kills by the time my kitty race has exterminated all the others, particularly those ugly Bulrathi bears, delicious Alkari birds, and those weak and pathetic Humans; that's a kill rate of about 1 billion an hour.
By comparison, my average kill rate in an FPS game might be about 500-700 an hour, so I'd say mabye a frag every 6 seconds. (averaging it to 600/hour) Since I play arround mabye 500 hours of FPS play a year, that works out to mabye 300,000 frags per year. I've only really had mabye a total of 2 year's worth of playing FPS games (I played them much more lightly before this previous year), so I might put my human death toll at mabye 500,000; adding demi/sub-humans to the mix (such as the once-human Ettins from Hexen) might bump it up to a full million. For that total span, I believe I've only had my player killed maby 10,000 times throughout my entire time playing games; my UT2k4 kill ratio is roughly 30:1, and with single-player games, I simply don't die.
Wake up, George Lucas... The Matrix has you...