The tcPrettyEmail plugin sends email which is MUCH nicer than the default teamcity plain text email.
Debian Package Server
The tcDebRepository plugin transforms TeamCity into a Debian package server. Packaged artifacts are automatically scanned into the repository at the end of each relevant build.
The packages are available for retrieval in the structure expected by Debian package tools like apt.
The tcMonitor plugin gives you a quick view of the health of your teamcity instance.
The status page is retrievable without authentication, and is “grepable” for strings like ERROR and WARNING. This makes it easy to wire into your monitoring application.
Custom Build Invoker
The tcBuildInvoker plugin allows you to configure custom builds as a simple list of choices, rather than the free form (and sometimes confusing) Custom Run dialog box.