Preferred building materials
 

I usually use stone brick and spruce planks. Oak planks if no spruce. How about you?

It depends on what dimension I'm in.
Overworld: Grass, Stone bricks, oak planks and logs.
Nether: Nether brick, obsidian, bricks (clay variety), mycelium, cobblestone.

I haven't messed around with the end yet. Obviously obsidian and end stone. Probably ice. I've been wanting to use that more. It depends on what looks good.

Typically wooden planks, usually oak. Nothing too special, I know. My starting homes are typically either bored into the side of a mountain or made of cobblestone.

Well... I use everything, I dont really have a preferred block. But if I had to say, I'd say different colored wool haha I make a lot of pixel art and to get the cool flooring that I like, it requires wool. Oddly enough, nothing I have made has been struck by lightning yet

I usually make a cave in the side of a mountain but when I finish all the rooms I turn the walls stone bricks, the floor stone slabs, the ceiling normal stone and sometimes I add some glass panes for no reason other then they look nice :)

Depends on where I am in the Overworld. Typically, if I'm above-ground, I'll use Stone Bricks and planks of whatever tree is in the Biome I'm in (except Birch. Too light of a color for me). If I'm underground, I have recently started using Grass for the floor and Stone Bricks for the wall and ceiling. And whenever possible, Glowstone for lighting. Redstone Lamp for lighting would be even better, but those are rather resource intensive.

I generally like building with stone bricks, regular brick blocks, nether brick, and wood blocks (not planks). I like using these for the simple fact that they look nice. :P Oh and for lighting, I use Redstone Lamps that are usually implemented into the floor.

I dig a hole in the ground to make a starting base.

For me it depends on the materials available, so it tends to change depending on what version of Minecraft I'm playing [mainly what mods are installed].

For vanilla [un-modded], I generally build using stone brick in the overworld, netherbrick in the nether. Depending on if block damage is on or not [this really only matters in SMP], I may also use obsidian as an effective anti-explosion material, usually sandwiched between walls of stone brick.

For technic/tekkit, the obsidian is replaced with reinforced stone, which is expensive to make but very explosive-resistant. Until I can afford to make a lot of reinforced stone, I sometimes used construction foam, which is also fairly explosion-resistant and can cover wires [construction foam can also be painted any color]. I also like the look of basalt bricks, since they're dark versions of stone brick. I sometimes use marble brick to highlight basalt brick when I want a nice black and white design.

I like to keep it simple with primarily oak planks. I use brick and stone to add some nice finishing touches to my structures.

I Love Wools and (non-plankified) woods. And Flowing Lava or vines. They look so awesome.