From Monterey Pop, my favorite performances from the original film (beside the obvious) include:

Canned Heat -- Rollin' and Tumblin'
Country Joe & the Fish -- Section 23
Eric Burdon & the Animals -- Paint It black
Jefferson Airplane -- High-Flying Bird & Today

From the outtakes DVD, I especially enjoy:

The Electric Flag (Bloomfield & Buddy)
Laura Nyro
Al Kooper Band & the Blues Project
Buffalo Springfield
The Byrds

Maybe this stuff looks 45 years old, but it doesn't SOUND 45 years old!