Okay.

Gold and Glory: The Road to El Dorado?

I think it's one of those Discworld games... but I never play them, so I do not know which one.

"Discworld II: Mortality Bytes!" ?

Yes!.

Okay - since my last one turned out to be difficult, here's an easy one this time. :)

VtM:Bloodlines :-)

Indeed. :) Your turn. :)

I don't currently have a game in mind, so someone please take my turn, or you can post another one :-)

Okay, then how about this one? :)

Advanced Civilization?

looks like it...

Yup. :) Quite a good implementation of the board game, even though the AI pretty much falls apart in the late game. Your turn. :)

Ok, I have run out of obscure classics, so this one is fairly easy, I guess.

Iron Assault?
I don't really think it is from the shots of the interface but the era must be close and it the only thing I've got...
LOL actaully reading the description of Iron Assault links to a game called
'Metaltech - Earthsiege'
Which appears to be the one you're after
Although there a couple games in the series so I may be one of the sequals...