My personal favorite would be almost any but the 1954 since I don't care for the grille styling of it.
I have a 1949 3800 series, which is a one ton. It rides rough (11 leaf rear springs), but then again I grew up with older vehicles and riding farm tractors, so rough I can live with. I also haul wheat or sand on occasion so need the extra springing.
Something else to consider is that ½ ton trucks use the torque tube, i.e. enclosed driveshaft, whereas the 3/4 ton and 1 ton use an open driveshaft. If you will be rodding/changing transmissions and engines it might be easier going with an open driveline.
However with the higher capacity vehicles also comes the funkier wheels such as 17" and 18" which make tires hard to come by at a reasonable cost, 16" would still be reasonable.
Now if I could just get those shocks that Wrenchbender spoke of----
