Here in Belgium, even in touristy places, you can always find a decent brasserie or casual restaurant where they serve the simple classics well, things like moules frites, a decent entrecôte, flemish stew, or even a simple pasta or burger.

There are bistros like that everywhere in France (minus the moules frites I guess :), maybe I'm used to spotting the nice ones but I've almost never had a bad experience with them.

Next time you should check on le fooding like I said above, that's what I use when I'm in a new place and so far I've never been disappointed.