Like many things when it comes to guns/ammo/self defense, it will start a Holy War of opinions.
Here is my $.02 worth...
If you are looking for the most accurate ammo, Federal 148 gr., Hollow Base, Full Wadcutter ammo is about as good as you can get. BUT, your 442 has neither the sights or the trigger to gain from that type of ammo.
If you are looking for range/practice ammo, any of the bulk 130 gr. Full Metal Jacket ammo available at most gun shops & WalMarts is good for that purpose.
As for carry ammo, I'd have to say the Speer 135 gr. Gold Dot for Short Barrels is the way to go...
Buffalo Bore makes a good self defense round for the 38, but it's loaded HOT, and isn't fun to shoot in a small/light gun.