Sample database schemas for different db types

I'm looking for some reasonably-complex database schema examples that I could use for examples on my site http://sqlfiddle.com (my current examples are pretty pathetic). I am aware of AdventureWorks and Northwind for SQL Server, but I have not heard of other "classic" examples for the other types of databases I support: Oracle, MySQL, PostgreSQL, and SQLite. Ultimately, I would like both interesting and familiar circuits and some interesting queries like "Sample Script" for each type. However, at the moment I am only looking for a schematic; requests may come later. Please point me in the direction of some of the interesting schemas for each type of database.