Between the archaeology skill and investigating the ruins I enjoy archaeology more. It was my unrealized childhood dreamjob and I did a few elective courses relating to archaeology at uni. Recently I tore down all the old buildings in Windenburg old town and before I'm going to build the neighborhood up again I let my archaeology students run loose on the lots, with tents, microscopes, chemistry stations and dig sites pulled from debug mode.
But what I love most about the actual pack is exploring the jungle: the chance cards that actually take my sims' skills into account, the survival feeling, the many screenshot/painting/photography opportunities, the creepy crawlie attacks, building basecamps and I even brought home a stray dog once.