Squid works wonderful.
What will fit - it is generally classic! I put it on all new FreeBSD-gates, which must be raised. There is nothing to say, flexible configuration of users, sites, bans for overpayment limit, reducing the speed of access in different versions - a song))). And in addition to this cache, which saves an average of 30% of the traffic. Many thanks to the developers, great! PS I would like to see in future versions of the MAC acl. THX!!!