It depends on the individual device. The dual logo sensors use a proprietary frequency which is neither zigbee nor zwave and which work only with that specific model hub. Some of the other devices are Z wave. And the smartthings Single logo devices are Zigbee.
The dual logo devices on the proprietary frequency are not mesh network devices so no repeaters are needed for those. They have a longer range than either zigbee or Z wave and are supposed to work up to about 350 feet from the hub, although it depends on local architecture and conditions.
As far as repeaters for Z wave or zigbee, it depends on what specifically you were looking for, there is no one best.
The least expensive zigbee repeater which also happens to be one of the only ones which will work for the inexpensive xioami devices is the IKEA Tradfri plug in Switch.
Otherwise, all repeaters, either zigbee or Z wave, work about the same so it just comes down to what are the other features of the specific device that you want. But there are many threads in the forum about repeaters, so you can just search for those. Again, though, you do not need any repeaters for the dual logo proprietary frequency ADT devices as that is not a mesh protocol.
Some reference threads: