There are lot's of Webmin modules which rarely have practical use and most probably they are for home users. However, in most cases we use Webmin/Virtualmin to manage our servers, not home computers, and it is really important to get rid off all unnecessary modules that are automatically installed, loaded into memory and are just sitting there and consuming server resources for no purpose.
So I would suggest to reconfigure the Virtualmin installation script in such a way that it does not load the following modules by default, leaving them available in Webmin's repository (http://www.webmin.com/standard.html), so that whoever needs could pull and enable them any time.
Jabber IM Server
Java File Manager (because we already have excellent File Manager module)
PPP Dialin Server
PPP Dialup Client
Samba Windows File Sharing
And these are just several modules that any Virtualmin server located in remote data-center simply does not need at all.
You would need some of the following Webmin modules If you are building more complex and sophisticated setup, but chances are you never use some of the following modules that have been loaded to your system by Virtualmin installation script:
Virtualmin Mailman, QMail Mail Server (because we use Postfix and Dovecot), ADSL Client, Bacula Backup System (not sure if this one does have anything with Virtualmins in-house backup system), Exim Mailserver (because we use Postfix and Dovecot), Fail2Ban Intrusion Detector, Heartbeat Monitor, IPsec VPN Configuration, Kerberos5, LDAP Client, LDAP Server, LDAP Users and Groups, Linux Firewall , Linux IPv6 Firewall , Linux RAID , Log File Rotation , Logical Volume Management , MIME Type Programs , MON Service Monitor , MySQL Database Server , NFS Exports , NIS Client and Server , Network Configuration , Network Services , Network Services and Protocols , OpenSLP Server , PAM Authentication , PHP Configuration , PHP Pear Modules , PPTP VPN Client , PPTP VPN Server , Partitions on Local Disks , Perl Modules , Postfix Mail Server , PostgreSQL Database Server , ProFTPD Server , Procmail Mail Filter , Protected Web Directories , Read User Mail , Ruby GEMS , Running Processes , SMART Drive Status , SSH Login , SSH Server , SSL Tunnels , Scheduled Commands , Scheduled Cron Jobs , Scheduled Webmin Functions , Sendmail Mail Server , Shoreline Firewall , Shorewall6 Firewall, Software Package Updates , Software Packages , SpamAssassin Mail Filter , Squid Proxy Server , Squid Report Generator , System Documentation , System Logs , System Logs NG , System Status , System Time , System and Server Status , TCP Wrappers , Text Login , Traffic Monitoring , Upload and Download, WU-FTP Server , Webalizer Logfile Analysis , iSCSI Client , iSCSI Server , iSCSI TGTd , iSCSI Target , idmapd daemon.