There are 4160 SCC judgments in CanLII's database — a complete set from the beginning of 1985 up to the present, and an incomplete set earlier than that. Essentially, the pool from which to draw is that of all cases in the last 22 years. I took the most-cited 1000 cases as my sample and first simply listed them in rank order, along with some information about each. I've created a simple html list of these cases and as well a more pleasing spreadsheet database display using Zoho Creator. Each case name is linked to the CanLII report of the judgment and each is accompanied by the CanLII keywords describing it and the number of cases that cite it, in turn linked to a CanLII search producing those cases as a result.
In addition I graphed the number of citations for each case, in order to see how the "influence" of SCC cases fell off. Unsurprisingly I obtained a pretty good example of a long tail: the number of citations drops precipitously for the first hundred or so cases and then slows its descent until around case #500 or so it tails away in a long and very gradual curve. You can see a crude version to the right of this paragraph, a better graph of the first 200 cases here, and the full graph here.
The winner in the most-cited sweepstakes (2336) by a very large margin — the precipitous drop, remember? — is R. v. W.(D.)  1 S.C.R. 742, a case on "charge to the jury," likely because this is a particularly vulnerable moment in a criminal trial and it is hoped that by invoking the highest power all will be well. Fully 545 cites lower comes the number two case, Pushpanathan v. Canada (Minister of Citizenship and Immigration)  1 S.C.R. 982.
What is one to make of all this? Not very much as it is. After all, this crude sort compares apples, oranges, pears and every other species of fruit. More… fruitful would be an analysis of influence that explored defined subject areas. And, too, one would want to see how a Supreme Court judgment was cited: that is, was it applied, distinguished, mentioned, etc. etc. But now that the number of cites can be delivered regularly by CanLII, the business of describing influence has become easier, which is a good thing.