LogFAQs > #964027073

technically correct uninteresting answer is probably MOO3. though I didn't really play it enough to tell for sure. (I remember it being almost fun to build up your planets, but there wasn't much beyond that.)

otherwise, maybe Earth 2015? if I recall, it has no upkeep or farm-space. the limit on how many units you can build ends up being a limit of physical space and room to move, even for air units. units, even air units, can't overlap. (maybe air can overlap with ground). so the end result was that your army can always be larger and more unwieldy, which was not a great way for a game like that to play IMO.

(in retrospect I suppose units taking up space and having to deal with the logistics of moving them is in itself a logical cost to pay for having a large army, but there needed to be some other kind of penalty for overly large armies, like upkeep. the way it was, you can pump out units till the game crashes and then find that you can't move them because they can't path and are just flooding your entire base.)