Fins are somewhat application specific. Although they are fair for general use, the real area where the Jet Fins (and their variants) shine is in silty enviornments where a frog kick is used. For drysuit divers there is the Trutle fin, a Jet fin copy with super large foot pockets. The other very popular conventional open heel fin is the Mares Quattro. Diver magazine got good results with the inexpensive Sporasub Twins.
See this recent test based on top speed:
http://www.divernet.com/equipment/fins0902/finsintro.htm
This 1999 test is for static thrust, many of these fins are still around:
http://www.divernet.com/gear/fins999/fins999.htm
Different application? How about warm water boat diving, or shore diving from docks or sandy beaches. Nothing can beat a slipper fin. Fit is critical here. Brands to try: Mares (all except Race), Technisub (stratus fp and Ala), Cressi, Aeris etc.
Split Fins: nice for swimming around in a non silting enviornment when slipper fins can't be used due to rocky entry or cold. Usually expensive. Photographers often don't like these as holding position is difficult. Main advantage is an easy kick and freedom from leg cramps. Brands to try: Apollo, Atomic, Tusa, Scubapro.
For an intersting fin test check out this link:
http://www.ndsu.nodak.edu/instruct/grier/fins.html
The author found a correlation between top speed, static thrust and air consumption (efficiency).
Also Rodales:
http://www2.scubadiving.com/gear/fins.shtml