If you go through a ton of strings, there's a lot to be said for D'Addario's bulk boxes. These give you 25 sets of strings per pack, in a much more practical way than buying individual sets one by one. A package like this is invaluable for repair shops, luthiers, guitar techs, collectors, educators and pro musicians. The more strings you use regularly, the more sense it makes to pick them up in economical bulk boxes.
D'Addario also caters to extended-range guitar players with sets that include all the strings you'll need, so you won't have to worry about mixing and matching. If you play an 8-string guitar, for example, look for packages like the EXL 120-8 and 140-8. On the other hand, if you find that you have one string that needs replacing more often, for any range guitar, D'Addario still has your back with individual strings. As many or as few as you need, you're all set.
Considering the impressive variety of great-quality strings that they have to offer, D'Addario is just plain hard to beat. And frankly, that's a good thing. It's nice to know that there's a brand you can always trust to have exactly what you're looking for, no matter how niche or mainstream it is. When you need guitar strings, D'Addario should be at the top of your list.