Really which material you decide to use depends on what kind of formicarium you want to build, or that you think would work best for your ants.
Acrylic is good for flat, hygienic 'layered' nest types for (typically smaller) ants that prefer a drier home. Acrylic is also versatile in that cutting, drilling, and gluing are all pretty easy, not to mention it's usually see-through, allowing you to really monitor the health of the hive and make it easier to tell when it needs cleaning.
Grout or other stones are good for damper nests with larger ants, and it really is pretty easy to work with considering you just pour it into a makeshift mold and the whole nest is a solid brick.
Wood and/or cork is okay, but really only if you have a wood-loving species, otherwise stone and plastic are superior because they don't rot.