There's a bit more to it than that. It is pretty simple, yes. But I said it featured heavily. Not that it was a detailed simulation of farming.

Pharaoh?
Several maps has the flooding and ebbing of the Nile as a piece of the puzzle, with farms (for figs, barley, lettuce, and more) requiring being placed on the area that gets flooded (only farms and roads can be placed there), and work camps close enough on the safe shore (try not to drown your workers).

One of the top five, strangest threads I've ever seen in my life.

There's always the much underated capitalism 2, plenty of farming in that, but it's not a very involved process. More a case of "make me a farm that produces cotton, watch money drain out, receive cotton.".

Sadly not on GOG, but it might be worth tracking down a copy of Sim Farm, which was a rather decent little game. Not as good as Sim City, obviously, but still a nice change of pace.

It may be a different topic, but it's not too out there. Farming is in many strategy games if even with just a small bit of content in this regard, such as just building a small farm and having it produce crops for your own people, but some games let you sell goods. In games like Civilizations and Alpha Centauri farming is important for the survival of your people. Some games even let you trade goods that you farm with other civilizations. It's just good to see a variety of content in games, and a game with farming would most likely be a strategy game, I would think.

Some of the most fun I have in games, online or off as I've played lots of MMO's, is collecting things, crafting things, growing things, and selling things. It could be anything from crafted goods from a smith or woodworker from collected ore and wood, to growing crops and making sales. I figured of these, growing crops is the least talked about. Being an obscure topic just reinforces that :)

Very unusual topic but not out there, I know. Not like a thread asking for games that have giant dildos you can beat people with(Saints Row 3).

I've never seen farmville, so have no idea whether it's like it or not, but you might want to have a look at this game on Kongregate.

Farming plays a central role in the Harvest Moon and Rune Factory series, but these are sadly not on GOG :(

Knights & merchants & settlers both include farm management as part of the general supply chain.

I've eyed those games for years. I should get one of each, Harvest Moon and Rune Factory
I've been eying that game too. Might check it out very soon. Maybe I'll be lucky and it will be in the summer sale.
Yeah...giant dildos is a bit bizarre ;D

A game that hasn't been mentioned yet is Patrician 3. It's best described as an economic/trading sim. However, crop production actually plays an important role in the game. The farming mechanics are fairly simple: build a farm. There are quite a few crop choices: Cotton, hemp, wool, meat (sheep and cattle are farm products in the game), grain, grapes (for wine), honey (via apiaries).

These basic farm products not only provide for the citizens (a critical component to creating a robust trade network), but also contribute to the proudction of finished goods. Also, cities vary in their ability to efficiently produce certain crops so that has to be taken into account.

It's not a particularly 'active' element to the game, but it is sneakily central to one's success.