MetaCrawler - http://www.metacrawler.com
The oldest metasearcher, and still the most popular, MetaCrawler searches nine large indexes, eliminates duplicates, and presents the results in ranked order. The address verification is worth the slightly longer processing time. Some advanced features.
ProFusion - http://www.profusion.com/
From the University of Kansas, ProFusion has a bare-bones visual style. It searches your choice of nine search engine indexes, removes duplicates and ranks results. Some Boolean searching and optional address verification are also available.