I have too many to name honestly but one that comes to mind (but not really “big”) is a travel router.
It’s amazing being able to VPN into either my cloud server or home network all over an encrypted WireGuard tunnel. I use the same SSID/password as my home network so that I only connect the travel router itself to whatever network (Ethernet, WiFi and even hotel WiFi with the terrible portal) and all my devices just automatically get online.