In Ruby, I have always been extremely fond of the Sequel ORM - http://sequel.jeremyevans.net/

The amount of expressiveness and capability it gives is simple outstanding. It lets me drop into pure SQL as well as write statements which are simpler and easire to grok when I'm using the ORM level abstractions.

Sequel for SQL users - http://sequel.jeremyevans.net/rdoc/files/doc/sql_rdoc.html

Cheat sheet - http://sequel.jeremyevans.net/rdoc/files/doc/cheat_sheet_rdo...