What game speed do you play on ?

1x

Don't remember the X but I play on Faster.

If you're playing it in single player, play what's comfortable.  For online multiplayer PvP games on the Diplomacy expansion, the speeds are set to all "Faster".

8x till the games slows down, then I dial it down slowly

so he's asking about the update rate, which scales the speed of the whole game on the fly. some of the answers here are about the game speed options, which is not changable once you enter the game.

If I plan on playing at regular update rate throughout the game, I am planning on a longer game (even though all game speed options are set to 'fastest'). If I want a quick game, I drop the game speed settings to normal, then increase the update rate in the game. It can make for some slow finishes at times if the fleet sizes get very big and theres alot of planets and I am forced to lower the update rate

1x pretty much all the time, except in some slow moments where I'm just rebuilding I might increase the game speed.

Normal speed is generally what I play on, unless it is multiplayer than its whatever the host has set.

1x normal speed....that way I can play civ 5 at the same time...

1x

Super slow mode. aka -5.0

That way I can play SINS, Star Ruler, AI War, and SoTS. At the same time, or any combination of such.

x1 during battles, x2 when doing generic stuff, x4 otherwise

Lately I've been at 2x, although if a really large battle (or more than 2 regular size ones) comes along, 1x. Late in the game w/ more than 5 AI.... 1x... gets too dang laggy for faster than that regardless of circumstances.