I suppose the Low "G" On an 8-string guitar.
I use Ernie Ball Hybrids for my Schecter and Epiphone
I use Fender medium Bullets for my Squier Strat (eugh...) and will use them when I buy my Telecaster.
Dean Martin Blue Steels for the two Yamahas and the Ovation
I use D'Addario classical strings for my Ibanez 3/4 Classical
For my Washburn Bass, I use the Ernie Ball Power Slinky Bass
I think the strings really make a difference. That's why I mix and match for perfect tones (the Hybrids are fantastic on the Schecter)