Hey!
A good poutine is at the same time simple and complicated. The best poutine is still the standard version. If someone can’t make a good standard poutine he should not bother trying to make a fancy one. The standard poutine has to have the following elements:
Good fries
Good fries are the base of the poutine. To me they have to be double-fried using, preferably, peanut oil. They have to be crisp enough on the outside to withstand the sauce but steamed and creamy inside. I like them golden and slightly sweet. Looks roughly like this:

Good sauce
That is the most contentious element of the poutine. All fries enthusiasts have their version of favourite fries and most poutine amateurs can come to an agreement to the elements leading to the best cheese to use but the best sauce leads to pretty strong discussions.
You have to understand that the original poutine sauce was essentially a the standard BBQ sauce that came with fries. The poutine was born when a guy asked the owner of a greasy spoon to put the cup of sauce and the content of a plastic bag of locally produced cheese they were selling on the counter in the brown bag that held the fries. The owner of the greasy spoon is said to have told his customer “its going to be a hell of a poutine”, meaning “its going to be a hell of a mess”. Since it was a small city, people started to order a “poutine” and the trend was born. The place still exists (its called Le Roy Julep in Drummondville) and it is interesting to note that the biggest challenge they had was developing a container that didn’t rip from the contact with the sauce.
I had the Roy Julep poutine and the BBQ sauce on it is pretty special. It seem to have a tomato base and seem to be slightly sweeter than other poutine I had. You have to understand that the poutine sauce evolved to a point where enthousiasts (should we call them snobs?) insist that any sauce not clearly labelled a “poutine sauce” can not be used in a poutine and that, no, a BBQ sauce is simply not the same.
Actually, what we call “BBQ sauce” does not have the consistency of ketchup. Its closer to gravy. If you can put it on an hamburger without spilling its too consistent. If it is too runny to put in a hamburger and you have to dip something in it (like a piece of chicken) then it should be of the right consistency. Think of “hot chicken” sauce.
I tend to be more flexible in my selection of poutine. Want to find a good poutine sauce? Order a “fries with sauce” (a “frite sauce” in french) and ask yourself if you like it. If you don’t have “fries with sauce” in your region try to find a place that does gravy to dip chicken in.
Here’s a recipe that looks ok at first glace. The chef is a well known tv show chef here. Caution: I haven’t tried it.
http://www.ricardocuisine.com/recipes/4854-brown-gravy-sauce-for-poutine-and-hot-chicken
Cheese
The cheese used in poutine is called cheese curd. It is also sometimes called “squeeky cheese”. Its essentially fresh unprocessed cheddar. It used to be sold in corner stores and greasy spoon all over the province of Quebec. If you are lucky enough to live beside a cheese producer they will sell it in bulk day fresh. Fresh cheese will squeak under the teeth. It is not essential that the cheese squeeks and even in Montreal finding curds fresh enough that squeeks can be hard so don’t worry if yours doesn’t squeek. A poutine needs cheese curds however in order to be a poutine. Any other cheese doesn’t work. Its the cornerstone of a poutine. Without proper curds its just a fries with sauce and cheese

Poutine alternative
Some early poutine variation uses spaghetti sauce. Its called an italian poutine and its not really a poutine but close enough. When I was young there were only two styles of poutine: standard and italian.

Some greasy spoon uses shredded mozarella instead of poutine. To me its not a poutine.

If you have all the ingredients right, the quality of the poutine will depend, on my humble opinion, to the quality of the fries. Other will say, however, its the sauce. Cheese is binary: its either the proper cheese or its not. Squeeky fresh cheese help with with crappy fries its still a crappy poutine.