All of these lovely fantasies have problems. The hex one adds complexity to the construction for no particular reason. The water tower on the roof becomes a single point of failure and will tend to want to freeze up. Caves would be nice, but what are the odds there'll be convenient caves located right where they want to set up camp? All of them would be complicated to build on Earth, never mind by a guy in a spacesuit
What they actually build will be an extension of our oldest and most mature design school - the square. They'll bring Titanium or Aluminum I-beams and bolt them together. For the sake of discussion lets assume a cube ten meters on each side, maybe an overhang all around the top. They'll bolt cross pieces and panels across the top and pile up regolith on the roof for the first layer of radiation protection.
Once they have this they'll go underneath and set up pressurized tents (if we can find suitable material for local conditions.) If tents work, they keep them. If tents are problematical they'll start building room sized cubes. The cubes will be essentially the same as the outer shell, but smaller and with caulked joints. As time goes by they'll start linking them. For safety reasons, internal air locks will be common. Water will be stored in flat compartments in the ceiling of each cube or tent as secondary radiation protection. Each room will have its own ceiling tanks so the loss of any one unit won't cripple them.
I assume they'll have a number of tanks of liquids and gasses - Nitrogen, Oxygen, Water, whatever else they need. Up on top of the regolith layer would be the place to store them. They'll be close to hand but out of the way, and if a tank fails there'll probably be no shrapnel issues. They will also lend a little bit more radiation shielding. If they have excess sewage it will be frozen in blocks and left on the roof for the same reasons.
The above feature will combine to something that has all the style and grace of a junkyard shack, but hey, it'll be easy to build, can be grown in stages as time allows, and it'll work.
My apologies to those fancy design guys...