He's probably asking for recommendations...
I've used Ernie Balls, D'Addarios, GHS and Everlys.
If you want something affordable and good, go for D'addarios and Ernie Balls. They feel very good and sound very good too, and stay in tune. I've only performed with D'addarios though, and although they're slightly more painful to play (from my experience that is) they're solid and reliable strings. And they sound a little better than Ernie Balls.
If you want something higher-end yet affordable, there's Everlys that you can only order from local online store Bluegrasswoods (Google it, the website's only a few clicks away). $11 a pack for the B-52 bombers, and were they awesome. Best-feeling strings I've ever played.
GHS... I wouldn't trust them on-stage. I've had random incidents of GHS strings snapping on me, even relatively new strings and even with regular wiping down. They stay in tune, sound good and feel nice, but I wouldn't be surprised if they broke on me. And set after set, they've let me down in some way. The only good ones so far were the GHS Silk and Steels for acoustic guitar that were on my Yamaha F310. Other sets I've used were disappointing. Once you perform on stage, you'll realize that strings is something you have to be really careful about. Not everybody can have two guitars or more on stage. One bad experience, and that company's over for you.
Funny thing is, other people seem to be having good experiences with GHS strings. Guess I'm just unfortunate in getting all the 'bad' sets.
Dean Markleys... I only tried their acoustic strings, and they're very nice. Nice tone, and the Alchemys last and keep their tone for a long time. The Alchemys are coated strings (google it if you're not familiar with coated strings) and I'd definitely turn to Alchemys if I wanted coated acoustic strings. Electric strings... I can't comment but I heard Blue Steels are good.
So that's it for me.. I don't experiment very much with brands, but I don't stick to just one brand. But one bad experience with a brand, and it's all over. I'm not using that brand on-stage...