WordPress MU

I'd like your opinions on this.

What plugins do you find valuable, useful or indespensible for your WP MU site?

I found BuddyPress yesterday, thanks to a post on this forum and I hadn't found that doing Google searches on MU plugins, so I'm wondering what else is out there that could be useful.

Are there plugins you use that add a particular functionality that you couldn't live without or that transform your MU site into something fantastic?

I'd just be very curious to have such a list as a resource :)

Thank you!

Sure, here are some I gotta have on any WPMU installation:

New blog default categories plus search and replace
http://wpmudevorg.wordpress.com/project/new-blog-default-categories-plus-search-and-replace

New Blog Defaults
http://wpmudevorg.wordpress.com/project/New-Blog-Defaults

All in One SEO Pack
http://wordpress.org/extend/plugins/all-in-one-seo-pack/

WP-CMS Post Control
http://wordpress.org/extend/plugins/wp-cms-post-control/

WordPress MU Sitewide Tags Pages
http://wordpress.org/extend/plugins/wordpress-mu-sitewide-tags/

And there are a few others, but these are in my "must install" list.

You may want to search the forums. There's like a half dozen of these threads already. Ever install is different.

I've searched the forums and I will continue to, but I wanted suggestions based on personal experiences and usage of MU people. I certainly know the ones I would suggest for a regular WP install from my experiences, and those I wouldn't. :)

Thanks grandslambert. I will check out all of those!

"Are there plugins you use that add a particular functionality that you couldn't live without or that transform your MU site into something fantastic?"

It depends on the site I'm working on. There isn't any one plugin I've installed on ALL sites.

"All in One SEO Pack"

I'd nix that. It's bloated and not really needed.

"All in One SEO Pack"

"I'd nix that. It's bloated and not really needed."

Really? I use it on my regular WP sites. Nice and easy to create custom page/post titles and descriptions.

I didn't ask for plugins that you use on ALL WP MU installs. I just wondered about those that you find particularly great/useful...