I generally go with 11's on my acoustic and 10's on my Les Paul. I've found that on every acoustic guitar i've had, I can get a good sound out of most gauges, but I think chords seem to sound better and sustain longer with thicker strings. On every electric i've ever had, I have always had a hard time getting lighter gauges to sound good because they tend to bend to easy and I usually fret pretty hard.

Oh, I highly recommend Elixer brand strings for both acoustic and electric. 2nd for me is D'Addario. I used to play Ernie Ball "slinky" strings and I liked them as well.