Quick Lunch in Ann Arbor
If you have a place to take it to (only seating is on the nearby stoop in good weather), hit Le Dog on Liberty between Thompson and Division. The soups are the thing, although if you like hot dogs he has decent ones (Koegel's). Ignore owner's brusqueness and irrational restriction of beverages. The soups are superior.
For pizza, I recommend Silvio's on North University. Eat it there. Italian as it gets, very good.
For a sub, get a cheesesteak at Joe's Sub Shop, on State between Liberty and Washington.