On the way to Gaspe- east of Riviere du loup
L'Auberge du Mange-Grenouille in Bic is awesome from what I remember. You should definitely give it a try. Also, you may want to take a look at the Voir restaurant guide, they do review a few restaurants east of Quebec City. I'll try to remember more places; I'm from Rimouski, but didn't have much fine dining in my youth...
Another Rimouski expat here. For seafood, head tp Capitaine Homard in Ste-Flavie. It's abour 20-25 mins east of Rimousi on the 132. Can't really miss it. If you crave poutine, go nowhere else than Cantine de la Gare in Rimouski located on the corner of Ave de la Cathédrale and St-Jean-Baptiste. I've many a poutine there after a long night at Sens Unique, a local bar.
Chez St-Pierre in Bic also gets good reviews. Local produce market driven cuisine. She also opened a more casual bistro in Rimousi on de la Cathédrale.
Just when you get off the 20 and onto the 132 in Cacouna, Alibaba is a gelatto place that is quite good if pricey. In Trois-Pistole, Fromagerie des Basques makes day fresh cheddar and a variety of cheeses. It's on the 132 a few kilometers before Trois-Pistoles. You'll hit a 70 kn/h zone and it'll be on top of a hill on your right.
There's also Les Trois Fumoirs in Île-Verte. Not a fish eater myself but I heard good things about them. They also make home smoked ham.
Thanks for input....a quick report:
1-stop at La belle Excuse in trois pistoles for qulaity dinner, good price, good people
2-stop at Ali baba gelatto on merge of 20 & 132
3-avoid at all costs, La Fromagerie basque in trois pistoles - solid cardboard
4-do stop at bakery in Kamouraska, opposite church
What cheese did you get at Fromagerie des Basques? While it's clear just from looking at them (and from tasting them) that their aged, smoked and fancy cheese are not very interesting, their fresh cheese curds are very, very good. I would say they are among the best I've ever had.