Depends a bit on your more specific use case / requirements and budget. Some require ongoing subscription costs. Some are harder to get your hands on if you aren't an authorized dealer. I dug up some links in another thread recently: Door lock system with keypad
Unifi Access is a decent option and they actually recently released a new 8 door controller the Enterprise Access Hub EAH-8 ($999, the single door controllers run $199 each) other hardware is required like a cloudkey or udm.
Kantech KT-400
Honeywell NetAXS-4
Most of the CDVI boards I'm seeing are only 2 door, I think there's a way to expand, but it isn't immediately clear.
The ICT Protege WX seems like a nice system and integrates an intrusion alarm, but is less DIY friendly, harder to get your hands on.
Brivo and Pro Data Key are also decent options that are harder to get your hands on and have subscription costs.
If you do go with a standalone controller that's network enabled, I'd make sure you enforce some external network security.
Dahua & Hikvision both make some less expensive access controller's that are probably better than some of the random Chinese brands on amazon.
Plus it offers integration via ISAPI(http requests)
Also pushing events to TCP server listener if you would like to recieve events in 3rd party apps or make your own