What I've been doing is firing up the S3D Model Viewer ( graciously hosted at
http://www.georgestools.chrsschb.com...eConverter.zip ) and going through each ZoneName_obj.s3d file. If there's a model of sufficient quality (e.g., no 12-poly boxes from 1998), I make a note to add the .s3d to my GlobalLoad.
I've added a couple dozen files chock full of models that way, and have been working the last few days on putting together a model menagerie on my server as an 'Art Test' zone for my own use, separating them into different categories (doors, buildings, crates & boxes, plants, etc.). I've set up on the Valdeholm moat. Lots of flat space to work with. It'll give me the opportunity to browse all the models of a particular category and pick ones out for customizing my zones with. Fun times.
EQG files also have models that can be imported, and they're more likely to be higher quality than the older .s3d files, but I haven't found a way to browse through all the models embedded in .eqg files yet. Might just end up figuring out a way to list all the *.mod files inside .eqg files and pop 'em into the world one by one to see what they look like.