So after many, many years of switching from smart home to smart home, we have finally found solid ground. We've moved from Rako (very early days), to Fibaro Home Center, to Smartthings, and finally to Hubitat, which we've been running now for about 2 years.
It has taken the best part of 10 years and LOTS of expensive device/sensor replacements, but I can now say our home is fully functional, completely self contained (offline), but most of all, RELIABLE! (ehem smartthings…).
If you're new and looking for guidance for common things then I'd like to help out. My No.1 piece of advice - Go Zigbee, wherever possible. It has been BY FAR the most reliable way forward. Forget wifi controlled devices, they’re a pain and they will clog up your probably already messy home network. Zwave.... we had zwave for 4 years, and we always had issues regarding the mesh/network, and it always seems to lag. Devices would also randomly become excluded (unpaired).
Right, let's start.
For lighting, obviously I'm going to recommend Philips Hue, it is just amazing, especially the dynamic modes, but if you're on a budget then IKEA Tradfri Bulbs (Zigbee) have proven to be extremely reliable, even the colour ones. Our entire house is now either Philips Hue or IKEA Tradfri.
For sockets, again, IKEA Tradfri Switched Sockets (Zigbee). They have all worked flawlessly since adding them (and we have at least 20+!).
For blinds, yet again, IKEA have your solution. Their Fyrtur Smart blinds are superb and pair directly to the Hubitat Hub. They’re battery powered (rechargeable) and will last about 3 months from a full battery (from what we’ve gathered). A third party driver (easily googled) is required to operate them though. They come in width sizes between 600mm to 1400mm, in multiples of 200mm. They drop up to 1800mm, but this can be adjusted and memorized by simply using the up and down on the unit.
If you need a Dry Contacts Relay Switch Module, for example to give a zero-voltage pulse for your electric gates or garage door, we've found the Samotech SM104Z (Zigbee) to work great. The wiring diagram provided only shows for switching Live (for switching lighting loads etc.), but you can just leave the switched Live disconnected and hey presto you have a Zero-Voltage Zigbee relay module! It took us AGES to find an in-wall module like this that had a proper clunky relay.
Of course, if you’re looking for an In-Wall Relay Switch Module for switching Live appliances, then the above module will also be your best friend.
BUTTONS ... Boy, have we tried and tested some buttons! Our daily drivers throughout the house are the Sonoff SNZB-01 (ZigBee). They’re reliable, pair directly to the Hubitat and the battery lasts ages. Oohlala driver is required to get them going though. They support Push, Hold and Double Tap. My only gripe is that you have to Hold the button for about 4 or 5 seconds to register as a Hold, not a Tap. We have around 30 of these dotted around the house with small Dymo labels on their face to remind us what they all do 
Other buttons we have are the Moe’s 4 Button Wall Unit (ZigBee) and the IKEA Styrbar (ZigBee). Both work flawlessly and are cheap as chips.
Sensors , again, everything we have is Sonoff and work from the Oohlala driver. PIR sensors SNZB-03 (Zigbee), Door Contact sensors SNZB-04 (Zigbee) and Temperature Sensor SNZB-02 (Zigbee) all work reliably and brilliantly. We have around 60 Rules/Routines that these are integrated into. Plus, they're cheap.
My guess is part of why we are having such good luck with the ZigBee platform/protocol is because we have so many ZigBee devices, most of which, the hard-wired ones at least, will act as a node/repeater to strengthen the ZigBee Network.
I hope this advice reaches any curious newcomer, it’s taken us a long time to get where we are with almost the entire house smarted up.
Not big deal considering how dirt cheap the switch is, but I'm hoping I can use it. My bedside night table needs a multi-button controller for Hubitat!
