The best fin is the one that meets your needs, for the kind of diving you want to do.
If you do diving where precise maneuvering is critical (like photography, or cave or wreck diving) then a stiff, blade fin is perfect. These fins also work very well in conditions where avoiding silting is important (like in Puget Sound!). Stiff blades allow you to transfer a lot of the energy of your kick to the water, but as a result, ask more of your leg muscles, so moving fast in stiff blades requires pretty strong legs.
Similarly, if you are going to work in area where there is a lot of fishing line, danger of nets, or where you are using line for navigation (think wreck diving in low viz), having a fin with a smooth outer counter and fewer places to trap line is important. Most blade fins qualify here.
If you are going to dive where a broken fin would be a disaster, you want to avoid models which have obvious weak points, like the "pins" on the SeaWing Novas. (You may also want to go with spring straps for those conditions, as well.)
If you are diving very thin exposure protection (so minimal weight), you may want to avoid very negative fins -- in that case, something heavy like Jets is not ideal.
If you are spearfishing, or some other activity that requires moving very fast, heavy, stiff blade fins aren't going to be the best choice.
Right now, I am using the Dive Rite EXPs. Their combination of relatively light material, fairly stiff (but not board stiff) blade, and longer blade for foot pocket size seems to work for all my diving, from single tank cold water, to single tank warm water, to cave. But I have bought a pair of the Novas for teaching, simply because there are times I need to chase down students, and I can swim faster using them. And I have a set of Deep See Pulses for pool work, because I needed something ultra-light to keep from being feet-down in the gear I use there.
The only fins I can't find a reason for are splits. Yes, they're less work for your legs, but if you need that much reduction in resistance to be able to swim, I suspect you'd be better served by a fitness program. They don't move as fast as Novas, they don't allow the control of blades, and it is very difficult to avoid disturbing bottom sediments when using them, even when in proper trim and executing a good kick.
