A good MasterCard that will get you 2% at Costco with no annual fee in the first year is the MBNA Rewards World Elite card. You can redeem your points for cash back, each point is worth 1% and you get 2 points per dollar spent everywhere.
For me, because i have a family, i like the
WestJet MasterCard. As someone else said, the cost saving on the first checked bag alone ($25X4 each way) is worth the annual fee. The companion ticket puts the card over the top for us. My wife and I use it to go to Florida every year. I don't use the card to collect rewards on spend, I just use it for the seats and companion ticket, worth the $99.
I like using a cash back card to collect on spend. No games, and my cash back can never be devalued like with points and miles.
I also like churning Aeroplan every year. Usually apply for 3-4 cards a year.