Berlin - you get fed really well there. It makes looking around the place very pleasant.
My wife thinks my criterion for rating major tourist cities based on how well they feed you without ripping you off in the process, is screwy. But I hate that ripped off feeling, and that perpetual having to look for a Burger King/MacDonald's for some meat feeling.
My criterion puts Venice down the absolute bottom of my list, with Rome and London down there too, Madrid faring a bit better.
Surprisingly, Florence was a pretty good place for food at reasonable prices.
Zagreb was great value too.
Vienna and Prague were in the middle rankings.
Paris would be pretty high up on the list, if they didn't always rip you off on the price of a glass of Coke.