I was watching My Man Godfrey and was struck by the title sequence and its use of typography. Older films generally have the credits first, this one is no different in that respect, but the integration into the film is quite phenomenal — the camera pans across a cityscape, with the cast, crew and title, displayed as blinking signage. The film is now in the public domain, and available for viewing on Google video or download from the Internet Archive.
On a somewhat related note, I thought the title sequence for Bored to Death was quite well done. Although, it’s more in the vein of typography as illustration.
Update: Added graphics from two title sequences. Also thought I’d take a moment to mention Christian’s Movie Title Stills again, which I linked to earlier.