It depends entirely on what you're looking to study and whether its at the undergrad or graduate level, the gold standard for Canadian university rankings has usually been Maclean's magazine's annual univeristy rankings, although in recent years, many universities have boycotted it over biases in the ranking system:
http://oncampus.macleans.ca/education/rankings/
I have friends who've studied at McGill and according to many, its not really that great and the school rides on its prestigious reputation. Obviously Canada is a huge country and your experience will depend entirely on where you choose to attend. Some of the best undergrad schools in Canada are in my home province of Nova Scotia (there's something like 11 unis there) with St. FX and Acadia being on top, for business, my Alumni, St. Mary's University is the best business school on the east coast. Mount Allison is a decent school, I have friends who went there but unless you're very active in school activities, you'll be bored to tears in Sackville, NB.
I recommend a smaller school in a smaller city for your undergrad, so the unis in NS are a good choice, another decent one would be
Bishops University, which is located in Lennoxville, Quebec, about a 15 minute drive from the city of Sherbrooke (I lived there for a few months, nice city) and 1.5 hours east of Montreal, solid choice. In these smaller towns, you will have a good experience as the towns are focused around the uni and there's a lot of school spirit. Another uni I would recommend just because I like the city so much is the University of Victoria, my cousin went there and she loved it.
If you attend a school in a larger city like Montreal, Vancouver or Toronto, you won't have the same experience. Do your research, there's lots of decent unis in Canada, but some are in some pretty shitty towns: UNBC (Prince George), Brandon University (Manitoba), Lakehead (Thunder Bay), UCB (Sydney), you don't want to end up in those dumps for 3-4 years.
Honestly, I say go East Coast, I know so many people from all over Canada and the world who went to schools there and had a blast, although its not the best place to look for work after graduation.
Nova Scotia:
Dalhousie-Halifax, good science programs.
Saint Mary's: Halifax, Party/jock school.
Mount Saint Vincent: Halifax, 80% women, 20% men, need I say more?
The above three are all in Halifax, my home city, its definitely a party city and very livable, I highly recommend studying in Halifax, I posted a data sheet on the city if you want to search it.
Acadia: Wolfville (1.5 hours from Halifax), party school/jock, consistently ranking in top 5 undergrad schools in Canada.
St FX: Antigonish, (2.5 hours from Halifax), also party school, consistently ranking in top 5 undergrad schools in Canada, one of the coolest school rings I know, the "X-ring"
UCB: Sydney, (4 hours from Halifax), shit school in a shit town, don't go there.
New Brunswick (aka
No Funswick):
UNB: Campuses in both Fredericton (nice small city) and Saint John (industrial shit hole), good school.
St Thomas: Fredericton, decent school, very small.
Prince Edward island
UPEI: Charlottetown, decent small school, PEI can be boring but its very laid back and the people are really nice.
Newfoundland:
Memorial University: Its in Newfoundland so you'll be drinking heavily and you may not understand what the locals say, but its a party city in a legendary party town, if you can't get laid there, then cut your dick off. I hear the school is pretty good too.
There's quite a few universities in smaller towns in Ontario but I'm not overly familiar with them, I'd avoid any university on the Prairies. Hope this helped.