The G Watch R is the first truly circular smartwatch, and it's also the first to ship with quite so many watchface options - 18 in all. Here's every one, in both active (as in, the display is turned on and ready for interaction) and always-on (passive sleep) modes.
Left: Castle white, right: Red
Left: Hiking, right: Fitness
Left: Photos, right: Increment (like simple, but shows notification counter)
Left: Simple, right: Planetary
Left: Rings, right: Coordinates
Left: Dashboard, right: Reveal
Left: Digitalog, right: World clock
Left: Number, right: Moonphase
Left: Sapphire, right: Camping
So, there you have it - that's a lot of watch faces. Some of them have secondary information functions, too. World clock displays a second time in a city of your choosing. Number gives you the date and day. Moonphase shows the phase of the moon. Hiking displays your altitude and steps taken, and Fitness does too. Red, for whatever reason, shows the month.
I use Castle white.
Update: Not 20 minutes after I posted this, my G Watch R decided to get an update to Android 4.4W2. This update added six new watch faces, pictured below.
Left: GMT, right: Aurora
Left: Club, right: Dress
Left: Needle, right: Record