I'd always intended to try something with ENC28J60 but as @DrAzzy says it's a nightmare. Basically they only send/receive packets - so while you could probably handle UDP (at 10Mbits/sec) semi-easily to do TCP/IP you'd have to have your own TCP/IP stack built into Espruino.
Definitely worth looking at the WIZ5500 though - there are some lovely little boards, for example:
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I'd always intended to try something with ENC28J60 but as @DrAzzy says it's a nightmare. Basically they only send/receive packets - so while you could probably handle UDP (at 10Mbits/sec) semi-easily to do TCP/IP you'd have to have your own TCP/IP stack built into Espruino.
Definitely worth looking at the WIZ5500 though - there are some lovely little boards, for example:
https://uk.banggood.com/Geekcreit-W5500-Ethernet-Module-TCP-or-IP-Protocol-Stack-SPI-Interface-IOT-Shield-p-1600005.html
Costs around £5, is 100mbps, and should work great with Espruino.