The big three for me are Nanny's, Cella and Mitchell's Wool Fat, for the reasons outlined by Mikael. Nanny's would be my recommendation for starting out because it's so easy to lather, and very protective.
That said, I've used all manner of soaps and a few creams in a spirit of experimentation, and there are very few which are really unsuitable. It's largely a matter of finding the right consistency, robust but not so thick that it makes the razor drag. In many cases when the lather is right it takes on that glossy look Vinny refers to. Other soaps and creams which have worked for me include (in no particular order): Arko; Tabac; Palmolive; Prairie Creations; Taylor's creams; Henk's creams; MdC; P.160; Briallen's Honeyspice; Sunbury's soap; Godrej cream; Speick.