aptitude - high-level interface to the package manager
install Install/upgrade packages
# aptitude install package
remove Remove packages
# aptitude remove package
purge Remove packages and their configuration files
# aptitude purge package
search Search for a package by name and/or expression
show Display detailed information about a package
changelog View a package's changelog
update Download lists of new/upgradable packages
safe-upgrade Perform a safe upgrade
full-upgrade Perform an upgrade, possibly installing and removing packages
download Download the .deb file for a package
reinstall Download and (possibly) reinstall a currently installed package
clean Erase downloaded package files
forget-new Forget what packages are "new"
hold Place packages on hold
unhold Cancel a hold command for a package
markauto Mark packages as having been automatically installed
unmarkauto Mark packages as having been manually installed
forbid-version Forbid aptitude from upgrading to a specific package version.
why Show the manually installed packages that require a package, or why one or more packages would require the given package
why-not Show the manually installed packages that lead to a conflict with the given package, or why one or more packages would lead to a conflict with the given package if installed

-y Assume that the answer to simple yes/no questions is 'yes'
# aptitude -y install package
-s Simulate actions, but do not actually perform them.
-d Only download packages, do not install or remove anything.
-v Display extra information. (may be supplied multiple times)
-q In command-line mode, suppress the incremental progress indicators.
-h Help text
-V Show which versions of packages are to be installed.
-P Always prompt for confirmation or actions
-f Aggressively try to fix broken packages.
-D Show the dependencies of automatically changed packages.
-Z Show the change in installed size of each package.
-u Download new package lists on startup.
-i Perform an install run on startup.