Hey guys, I usually use Ernie Ball or D'Addario, but also Use GHS Boomers. These are the three brands that I can usually get for between 3 and 5 dollars a set when buying a dozen or more sets.
I also use some of the more expensive Ernie Ball Strings like Cobalt and Paradigm.
The Cobalts are a good choice if you have a humbucker equipped guitars that gets mushy sounding with the low end through high gain, especially on the neck pickup. They really tighten the low end up, adding some punch to what was once flub.
Also, I have some guitars that get played only occasionally. On those, I will use the Paradigm sets. Ernie Ball guarantees them against breakage for 90 days, but breakage aside, they don't become dull on the guitar, just sitting in the stand for months.
I have one guitar, that I've had these on for over a year, and the strings show no signs of corrosion or deterioration. And still sound like new strings.
The ones I usually don't use are the Pure Nickel strings, of any brand, as they sound dull within a couple of weeks for me. The only guitar that gets them is my 79 Hardtail Strat. They sound glorious when new, and that guitar doesn't get used much.