Who has the best internet fax site?  

If you are sending and receiving faxes, I use Fax thru Email. That way they can't charge you monthly fees and 10c/page for outgoing faxes.

If you aren't in the Phoenix metro area, you need to get a toll-free number for a little more per month.

https://www.godaddy.com/gdshop/email/fte.