Curl:
curl canhazip.com
curl ident.me
I noticed that in some cases the above returns an IPv6 address, to specify IPv4 do this:
curl ipv4.icanhazip.com
curl ipv4.ident.me
IPv4 from a different service:
curl https://ipv4.lafibre.info/ip.php
Wget:
wget -q -O - ident.me
Bonus, get the weather via curl: curl wttr.in