Kwikset locks have been my goto for Smart locks for years.  Even though you have many other options to choose from these days, it's their SmartKey functionality that kept me coming back as it allowed me to rekey any lock myself.  The Contemporary line they have is my favorite, but there are many styles to choose from.  Make sure to purchase the correct one when it comes to wireless integration (Wi-Fi or Z-wave) as they have both.  Check out my Smart Home section to understand the difference.

WiFi enabled and with a few more features, you really can't beat the eufy C220 smart lock.