Apple
MobileMe’s login screen is more than just an empty box. The depth charge approach gives you a peek at what’s behind the login and makes you want to “unwrap” it and get inside. It’s not surprising that a company that famously does a great job with product packaging would have an online product wrapper that stands out too.
Acrobat
Acrobat.com offers a login screen that lets you select from a variety of options. The focus shifts depending on which tool you select. And though the page doesn’t reload, there’s a distinct URL so you can link to a specific tool’s login.
Vimeo
Vimeo offers this playful login screen. Not really related to video sharing at all, but it does hint at the vibe of the community that uses Vimeo.
Any other login screens that you feel stand out from the pack?