Excluding the special types for 16" Brompton wheels, on the family bikes I have :
1 SONdelux
2 SON 28 Klassik
1 Shimano DH-3N80
3 Shimano DH-3N72
All work very well. I don't notice the (small) differences in efficiency between the different models.
For heavy use, I prefer the models with steel axles (SON 28 Klassik and Shimano DH-3N72), and use them with Allen-key skewers rather than quick release. The SON 28 "Der Standard" also has a steel axle.
The two dynohubs with aluminium alloy axles are now on bikes that are not used for carrying heavy loads.
Several years ago the SON was clearly superior to other hub dynamos. I am not sure that this is still the case, as the mid-range Shimano hub dynamos have been significantly improved.
I expect the SON hub dynamos should last longer, but probably not enough to justify the price difference in most cases. On the Rose bikes site the SON 28 is 210,76 Euros and the Shimano DH-3N72 is 59,50 euros.
Another possibility is the SP dynamos, these are between Shimano and SON in price, and seem to have good reviews.
This site has some interesting reviews of various hub dynamos:
http://swhs.home.xs4all.nl/fiets/index_en.html