In the south facing windows I keep potted pineapple mint, for mojitos.
We are looking at getting a lemon and/or lime tree as well... but this may involve moving out furniture so some negotiating yet to be done ;)
Everything I select to plant as an edible is something I use. I started years ago with herbs - the single biggest cash crop for my budget! I keep herbs in pots indoors all winter. Many are moved outdoors in summer, but are kept close to the kitchen and fetched indoors at the first sign of weather change.