There are multiple types of credit cards providing access to different lounges across the world. Within Canada, you can gain access to the following lounges:
- Air Canada Maple Leaf Lounges
- Delta Sky Club
- WestJet Elevation Lounge
- Priority Pass Lounges
- DragonPass Lounges
- Plaza Premium Lounges
- Centurion Lounges
- Escape Lounges
- Airspace Lounges
- Executive Lounges by Swissport
- National Bank Lounge at Montreal Airport
- Desjardins Odyssey Lounge at Montreal Airport
Some of these programs might overlap. For example, many Plaza Premium Lounges are also part of the Priority Pass and DragonPass program. You will need to complete your own due diligence to confirm which lounge network works best for your travel patterns.
There are fourteen different credit cards that provide lounge access in some form in Canada. Many of them have their nuances. Doing your own due diligence to confirm whether you should opt for Priority Pass or DragonPass is tedious. There is no clear resource to identify the differences in lounges. I do believe that Priority Pass is more extensive, however, that is driven by my only experience at Puerto Vallarta, where DragonPass did not have an affiliated lounge. But one airport out of thousands speaks little about what you may experience.
Rather than rank all the credit cards, instead, this article focuses on selected credit card for each style of traveler.
Best Lounge Access Card for the Infrequent Traveler

The Scotiabank Passport Visa Infinite provides six complimentary access to DragonPass lounges across the world. For an annual fee of $150, this comes out at $25 per lounge visit per person. In addition to that, the card waives foreign transaction fees, which is a great addition if you travel a lot outside of Canada.
Best Lounge Access Card for the Air Canada Traveler

The TD Aeroplan Visa Infinite Privilege has unlimited access to Air Canada Maple Leaf Lounges located in USA and Canada. In addition to that, as a Visa Infinite Privilege cardholder, you also have access to six additional lounge passes through the DragonPass network. This is a great alternative if you find yourself internationally or on another non-Star Alliance carrier.
CIBC Aeroplan Visa Infinite Privilege

The CIBC Aeroplan Visa Infinite Privilege has unlimited access to Air Canada Maple Leaf Lounges located in USA and Canada. In addition to that, as a Visa Infinite Privilege cardholder, you also have access to six additional lounge passes through the DragonPass network. This is a great alternative if you find yourself internationally or on another non-Star Alliance carrier.
The differences between the two cards are marginal, primarily the sign-up bonus and the annual fee for supplementary card holders. The American Express Aeroplan Reserve was not listed because they do not come with six complimentary lounge passes for DragonPass lounge as that is a Visa Infinite Privilege perk.
Best Overall Card for Lounge Access
Business Platinum Card by American Express

With unlimited lounge access for yourself and a companion (in most scenarios), across the world, this is by far the best card for lounge access in Canada. The business version of the card is consistently ranked higher because of the higher sign-up bonus available for the Business Platinum cardholder.
American Express Platinum Card

The benefits with the Business Platinum Card by American Express are the same. The only difference is, this card is the personal version, with a slightly lower sign up bonus.
Conclusion
There is no single best credit card for lounge access. The best credit card depends on your travel patterns. The five cards listed above are some of the best cards for lounge access, however, they might not be the best travel cards.