Closest thing I know of is Wiby, though that has more of a general ye-olde-web focus and i’m not even sure if it indexes Geocities. Would definitely be a fun project!
Here's one with an index covering Geocities, AOL, Angelfire, Tripod, Xoom, and perhaps more: http://oldavista.com/
Here in Neocities, celebrities are portrayed in a fictional dimension partially based on IRL factoids about them.
Woow, this X-Files site looks MASSIVE!