ball joints

I seem to replace ball joints every 40K miles on my 96 S-10. Are there any aftermarket ball joints that will last longer than the dealer supplied units? After the first 2 failed I made sure I followed recommended greasing intevals. Then I had another 2 failures. 40K seems to be the max I can get on a set. (I have 180K on the truck) THis is the first vehicle I've ever owned that I have had to replace ball joints on. It looks like my 99 Blazer is going the same way.

Buy nothing but Moog suspension parts.(not including shocks)
They are the best and should last a lot longer

How often do you grease them?

napa premium, lifetime warrenty, but they realy dont need it with their titanium ball joints, make sure its premo and not the std ones