They are both fantastic guns. For me, though, it would have to be the Sig. Glocks simply don't like me. They don't fit me well, and I am not a fan of the fact that the barrel is placed differently as a previous poster mentioned. This is simply because it is different than what I am used to. They are unbelievably reliable, but then again, so is a Sig. I have had several (220, 226, 238, and even the cheap 250), and they have all been fantastic, reliable weapons. They fit me perfectly for the desired function, shoot as accurately as any stock pistol I have had my hands on (other than a Colt Defender in .45 ACP...I know...a 3" barrel!!!), and look good.

At the end of the day, I think you would be best served picking up whichever fits you the best. You can't go wrong with either option.