I check creditcards.com about once a month to look for good deals. My current lineup:
Chase Sapphire Preferred - Daily use card plus the 40,000 bonus points for signing up and spending $4,000 in the first 3 months. (First year no annual fee)
AMEX Platinum - Use it for the perks, not for domestic purchases (Priority Pass Select, Global Entry, SPG Gold, $200 airline credit, no foreign transaction fee, etc). Annual fee waived for 4 years now
Barclay Card Arrival Plus - Used it for the 40,000 bonus points at signup, plus 10% back in points when redeeming. Dropped to regular arrival with no annual fee after 1 year. First year no annual fee
Capital One Visa Signature - Used it for 40,000 bonus points at signup, dropped to regular after one year for no annual fee.
Citi Dividend, Capital One Quicksilver, and Bank Americard - Used them for the $100 free dollars for signing up, and now just let them sit.
Chase Freedom - Just a good card to have, and Chase points are better than any other points.
Amex Blue Sky Preferred - Use it for the $100 annual airline fee reimbursement on top of the $200 reimbursement from the Platinum. Annual fee waived for 4 years now.
Plus store credit cards when the deal is good. (Macys, Pottery Barn, Target, Kohls, Home Depot, etc.)
I have never paid one cent in interest or carried a balance on any card, and in the last 5 years I've made about $8,000 in cash back, travel and rewards. I track my cards and rewards on a spreadsheet to ensure I never end up paying an annual fee.