For a four string set 50-110 would be my choice for D-standard. I've just been using 45-105 sets lately... Partly out of laziness because it's the easiest to find. However, the attack on the low strings definitely pulls a bit sharp, so I have to tune the attack to pitch and the decay goes a bit flat.
Dean Markley makes a 50-110 Blue Steel set that gives a little more string tension. As I recall, these were pretty good and would probably be my preferred choice for D-standard. If Dean Markley is hard to find, Rotosound makes a 50-110 set (Swing Bass 66), but I have not tried the Rotosounds in that gauge.