Goodlogo features a set of logo design cases that either show how a logo has changed over time or tell the story of how a logo was designed.
It also features a hot-or-not style logo beauty contest, and a logo of the day.
Cool site, but I have to point out their bad use of Flash for the AT&T case study (swf) - they have a little animation that shows you the AT&T logos one after another, with a little musical tune playing in the background. This looks very slick, but it's not very useful. I'd like to compare the logos, and to do that they should be arranged spatially instead of temporally. They did it right with the Fiat logos (though I don't understand the location of the gap in the grid), which makes this doubly frustrating. [another link via Zeldman - I like his site]