GHS Boomers- 10s for me. Used TNTs for ages, but then found the heavier lower strings were messing with the necks a bit more than I'd like, so just went for regular 10s.
Hmm -
Blue Steels - chewed up my frets, then I realized that they seemed to die pretty quick too.
Elixers - Loved them, lasted a long time, just a little pricy, but I'm a lazy bastard when it comes to changing strings.
Snake Oils - Last longer than any string I've tried. Totally worth it to me. Should buy some more soon...
D'Addario - Good strings that are easy to find cheap. Generally my backups (when I get lazy and don't buy Snake Oils).
Webstrings - Just bought a round. Haven't used them yet, but I'm looking forward to checking them out. Hopefully they are good, because I bought in bulk!!
Dean Markley Nickelsteel for me. I like how they feel and sound. I'm not super picky though. I don't really dislike any brands of strings that I've tried. Elixir's are overrated to me just because of how expensive they are. They don't feel or sound twice as good to warrant double the price.
my preference is for blue steels, but since i decided to tune so low i had to move to a 7 string set. the store i trade with only has d'addario 7 string sets, so that's what i use.