The best place to eat used to be Le Privilege, but it no longer exist as a restaurant, it's now some sort of catering project, but I had to mention it. Here's the website if you're curious.
The fanciest place around is Auberge Villa Pachon (especially if you like cassoulet) in Jonquiere.
Otherwise, in Chicoutimi I would suggest La Cuisine
If you feel like sushi (which is so representative of the local cuisine :p) apparently Temaki Sushi Bar has the best in the province
Now, if you're into greasy comfort food (not fancy dining), the local institution is Chez Georges steak house (aka le Steak house)
You can guess the type of menu from the prominent colourful sign. It's a classic but, again, don't expect a fancy, long dining experience.
There are various inns and inn-type restaurants around the region, I haven't been to any in ages, but I will say this: l'Auberge des 21 in La Baie is overrated. Don't bother with that one.
Since it was the feast of Saint Anne yesterday, blueberry season should be started. The famous Trappist made chocholate covered blueberries might be available as of this weekend, Be sure to buy some if you can, but don't fall for a knock-off.
For what it's worth, there's tasty poutine to be had at Capitaine Bob. Order with fromage en grains (not grated) and pick your sauce - "BBQ" or "hot chicken". Wash it down with a Red Champagne - a horrid soft drink available only in this region. Also, go to Fromagerie Perron to stock up on very old cheddar and other local stuff.
One place I don't particularly recommend is the restaurant at Chateau Roberval.
360, boulevard Marcotte
156, av Albert-Pérron