As a recent convert to vegetarianism, I find myself at Subway often for the veggie patty sub or the $5 footlong Veggie Delite.
Subsequently, I've been in a lot of Subways around Charlotte.
This is the best overall.
I've received consistently fast, friendly, polite and competent service, and I've never had stale bread here.
If you go around closing time, they sometimes offer free cookies.