Connect-a-Beam is a construction set that was designed to be easily 3d printed and assembled quickly. That means that it's reasonable large to print it with for example 0.6 mm nozzle and with no supports and you can snap parts together with connectors.
Advantages:
- printable without supports
- printable with PLA
- printable with 0.6 nozzle (faster and does not have to be that precise)
- big parts (at least most of them)
- quick & easy assembly, just click parts together with connectors
- extendable
- customizable
- open-source