Since I started working at a music store ive tried everything we carry for electric guitar at least 3 or 4 times. Heres what I can tell you....
Daddario - What I originally played since i was a little kid, They still make an EXCELLENT and consistent string. It's pretty much a stock or standard "safe" string that we sell to customers who don't know what they need. Pretty bright for the first day but then they die off fairly fast, Not a super smooth feel but not bad either. Good strings!
Dean Markley - Blue steels are a pet peeve of mine, to me they are kinda dull and just never last the way the should...Not reccomended by me, but i know guys that SWEAR by these. I had many problems with strings breaking here.
GHS - Another pretty stock string, These feel a bit rougher to me than daddario, They also seem a little duller in sound. They do stay that way though and are pretty consistent, Definatly last longer than daddario's
Ernie Ball - I love the feel and sound of Ernies, no matter what they are ... They have a certain smoothness and bite, they kinda SNAP if you know what I mean. Only gripe with ernies is that they really die fast. Other then that, they ROCK!
DR - Ive had such great success with some of there stuff, but not all of it. These are definatly picky strings! the DR pure blues work EXCELLENT on strats and Tele's , the compression winding definatly helps tuning stability and makes the string VERY smooth. Smoothest of all id have to say, they are a bit stiffer though so be careful with gauge selection. The DR tite fits are KILLLLLLLLLLLLLER on Les Pauls, they just go together like pea's and carrots. These strings last forever... not to mention they are great guys over there!
Elixer - To me these are decent but I just dont dig the coated strings, they seem darker sounding which i guess is cool if you wanted to tame a bright guitar a bit, But overall they just dont interest me a bit!
in conclusion , finding the right string is definatly a VERY personal thing, there are great things about all these strings and some work better then others on Certain guitars and for Certain styles...