Can anyone help me to make list of 6 defensive buildings for my game?

Pillbox.
Lookout tower.
Gun emplacement.
Tank factory.
Bank.
Sweet shop.
Postbox. (Essential, really, in all games requiring an accurate snail mail representation.)
Orbiting space station.
Martian Invasion Force Mother Ship (mark 2).
Cobra (mark 3).
Automated Cow Slinger. (French).

Thank you Squirm! But I need only defensive buildings. You said pillbox and gun emplacement, I need 4 more buildings like this.

trebuchet.
ballista.
vats of boiling acid.
:o

surface to air missile sites (SAMs)
Trip mines / other mines (eg movement detecting)
Flame tower (it''s possible though not realistic)
Huge tesla coils (quite possible though in theory it would discharge on everything grounded around it, so you could have your troops wearing insulated boots or similar...)

Thank you guys, but it is still not what I need. I need something like in other RTS''s (Red Alert or C&C:generals). Please give me more ideas. Thanks!

Defensive structures? I have one more: Machinegun Nest. Nothing more than sandbags and a heavy machinegun. Cheap, low-end.

I also say mines and SAM sites are especially realistic. Though SAM sites are useless unless your game has no aircraft.

Thank you all guys! I have finnaly a list of 9 defensive structures. What do you think about the name of building where your vehicles for gathering gold brings gold in? And what should be name of that vehicle?

crazy ivan is copyrighted by westwood

Yes, I know, I won''t us crazy Ivan.

For military hardware used in the past 50ish years by most of the world: check out www.fas.org.
for instance here is a list of land systems used by the US
http://www.fas.org/man/dod-101/sys/land/index.html
scroll down to ''individual'' and on the right is ''anti-tank/assault''. Theres your bazooka type dealies.