Drupal modules themes websites webdesign libraries php customization

It would be helpful if we could share details on what themes we are using and how they've been modified, especially front pages. Currently I am developing a site for Stony Brook University Libraries using the Beginning W2 theme, and I would appreciate learning what others use and why, and how you've modified it.

Related to this, I am bursting to learn how others have modified any of your *.tpl.php pages.

I will post more as I continue my design and implementation for SBU libs.

Thanks very much :)