Some plants I keep around only for their reliable blooms, like Kalanchoe blossfeldiana & houghtonii. The foliage isn't much to look at, but the flowers are stunning, show up readily inside during winter, and last a long time. They really put holiday cacti to shame in that regard. I'm not much attracted to that foliage either, or that of many epiphytic jungle cacti like Selenicereus and Epiphyllums. But if they ever bloom though, it will have all been worth it, every sweaty watering, repotting, moving of a heavy pot.
Billbergia is another one like that. The foliage just looks like some kind of weird grass. But when a bloom shows up, it's time to ooooh and aaaah.
Amaryllis. Foliage from almost any kind of bulb is a real snooze. More "giant grass" appearance.
I don't keep Callisia fragrans around because it's attractive, and even when it blooms, the flowers could be easily over looked. That one's all about sniffing the tiny, inconsequential looking blooms.