In a piece that is strongly identified with and by ostinatos, the "Procession of the oldest and wisest one" section of Stravinsky's The Rite of Spring is the standout, both in terms of density and number of patterns present.
In 20 measures of music (about 40 seconds) Stravinsky combines a BUNCH of patterns (I forget the exact count, and a count is tricky because some are doubled); the following pattern in the percussion is the foundation. The bass drum and tam-tam start before this; the guiro enters at measure 13 (:20) of the section:
Which brings me to the drum beat. If you substitute the tam-tam with snare drum and the guiro with hi-hat it sure sounds and looks a lot like this:
|a "characteristic drum beat" from Wikipedia|