I have a couple.

I have a Costco Am Ex that I use only for electronic purchases at costco. Costco doubles the warranty on things like computers and TV and other electronics so taking the decline in value over points makes it worth using this card for these purchases (for other costco purchases I find my Hilton card is worth more from the points). Advantages are no fee, 2% back on restaraunts and travel purchases and 3% on gas and 1% on anything else (You would think costco would do 2% on Costco purchases instead of 1). This is a great card if you can't justify paying the fee on a travel card. Also nice you don't have tiers to get up to the 1% like discover. Minuses: Not all places take AM EX and you only get one cash back check a year.

My main card for my first $40K in spending is my Hilton Surpass card. I signed up for it for it for the nice bonus and the first 8 hilton stays you get 2,500 bonus points per stay. I can't get diamond status the conventional way at hilton, but stay at Hilton enough the diamond perks are worth it and if you spend $40K in a year you get upgraded to Diamond. So I use this as my primary card for my first $40K of spending a year and once I reach Diamond I do continue to use it for hilton purchases (9 points a dollar) and place they give 6 points a dollar like gas stations, grocery stores and my wireless bill.

Advantages: You get Diamond status after spending $40K a year and gold for $20K a year (you can get the gold upgrade on the no fee card as well). 9 points per dollar charges at hilton, 6 points at gas stations, drug stores and wireless and 3 points elsewhere and you get gold status at hilton the first year if you are silver or lower already. Your first 8 or 9 hilton stays you get a 2,500 point bonus as well per stay. Minuses: Again not all places take Am Ex like Visa and MC and there is what I consider a hefty annual fee for a hotel rewards card.

After I reach $40K in spending on the surpass card and for all places that don't take Am Ex my Southwest Visa is my primary card. Pluses: Visa is readilly acceptable, you get 2 bonus credits on each renewal, sometimes you can get promos for a first time sign up for 16 credits which is enough for a free ticket, double points on southwest and all southwest hotel and car partner purchases, lots of various promos during the year from chase. Disatvanges-annual fee (which you do at least get 2 bonus credits a year for renewing), a few years ago they raised it from $1,000 in purchases for a credit to $1,200 in purchases for a credit.

One other card I have is a credit union visa I only use for foreign travel since the other cards I like charge some hefty surchases on foreign transactions. Pluses-No fee and no foreign transaction surcharges and the foreign exchange currency rate is fair. Minus-No rewards or points (which is more than offset with no foreign currency fees).

My favorite card used to be Diners Club. I loved their rewards with it and the perks were great. You used to get 20% off at any Idine member establishment which more than paid for the fee, the best rental car insurance out there and a few Airport lounges would give you free access with it. About 5 or 6 years ago after Citi took over they got realy stingy with the benefits so I cashed my points out and cancelled the card.