Panama Canal (LAX to FLL)
Tahiti (RSSC or TP)
A variety of Austrailia/NZ cruises (very port intensive)
The last two (or first two) segments of RSSC's Circle SA go from Buenos Aires to Manus (most upstream port on the Amazon) and Manus to FLL.
The Mexican Riviera (I didn't care for it, but it is a warm water option)
Greg