I have a couple of the Zooz Q sensors, and they aren't bad, but they're also pretty big (albeit symmetrical and not as long as the ThirdReality, which I've never seen in person). Like many Z-Wave motion sensors, it also tends to be a bit slower to generate a motion event compared to most Zigbee sensors, so that's important to consider if you're using them for motion-based lighting or other automations where timing is important.
If you're looking at price alone, it's hard to beat the Sonoff ZNZB-03. But you did say "not ugly," and lots of people might consider it to have failed that test. 
(They're pretty small though, and from far away it's not likely to be noticeable either way...) If the Iris v2 (3326-L/3326-L2) motion sensors were still available, they'd be my recommendation, but they're long discontinued and seem to be hard to find even on the secondary market now. The v3 isn't bad, either. The SmarThings sensor, now/soon to be manufactured by Aeotec, is also pretty good but starting to get on the larger side of things again. Something I haven't tried and therefore can't recommend but am tempted to anyway based on the manufacturer's reputation (they also made the Iris v2 sensors) is the Centralite Micro motion. Looks small, not ugly, and not too expensive...but no personal experience.
