I'm actually not a very keen houseplant person (they get neglected all summer while I'm outside), so the few houseplants I actually do own have to be extra special: anything that is easy to take care of, yet flowers, is definitely a worthwhile houseplant in my books!
Christmas cactus fits the bill:
People who've been over to my house recently have asked, "Do you fertilize your christmas cactus?" Why, yes, of course! It is a wonder to me that people think they can grow a plant in a pot for years and not feed it anything. I feed this the occasional 20-20-20 mixed in water from about March through to September (when I remember) and then stop. By now the plant has enough energy to flower and then I want to give it some downtime over the winter before it enters its next major growing season when the days start to lengthen again. This is growing in a sunny, west-facing window, BTW (and that's the Adventure Garden in the background.)
I also have a Meyer lemon tree which I acquired this past spring. It took a while to get settled in its new pot but seems to be doing OK now. It is everbearing so always has flowers on it - which smell AMAZING! I have yet to harvest a decent lemon but it's worth it just for the flowers. I can always hope for future lemons since it's early days still. I've also heard that these plants are fairly finicky about their moisture requirements... I'll have to do some research. Anyone have any tips for growing Meyer lemons?