The Christmas Cactus has always been one of my favourite houseplants.
Easy to care for, this seasonal plant generously spashes forth fuchsia that for most of the year remains hidden within the flattened leaf-stems. Even the most neglected of the Christmas Cactus (like that of one of my coworkers, which hasn't seen a hint of daylight for about eight years) will survive.
Ours shown above is hosting at least a single flower, and in many cases two, on each stem. It's also the only seasonal plant my parents have that will dependably break forth in bloom, unlike the poinsettia disappointments they regularly receive as gifts during this time of year.
Theirs, however, doesn't bloom till closer to Christmas, or sometimes well into February, as the blooms are timed with the shortening days, and artificial light throws off their timing. If yours has this problem, either shade the plant well once the sun sets, or just put it closer to a window/further from artificial lights. If your buds fall off before blooming, you may be watering too much. I've read that you can reduce waterings to half of what you normally do during the winter months, though I've never had to do this.