I always thought Command and Conquer was a blatant rip-off of Dune II when it came out, didn't realise it was the same team.
There'a also Utopia (although you don't actually get to see the enemy's city, you just send your tanks there and wait for the result) and its successor K240 (where you do get to see the enemy's bases and take them over).
Another good game that's quite similar, although rather more sedate, is Settlers.
