Here's another $0.02... You'll see that opinions vary widely.

(1) Step 1 - pick up all three major hotel cards. You can't lose with those. MR Visa, HH Amex, SPG Amex. MR Visa and SPG Amex have low annual fees and upfront bonuses that more than pay for several years' worth of fees. HH Amex is free and includes bonuses like perpetual Silver status and some upfront points. Worst case: you'll come away with it with a few free hotel nights and some low-elite statuses with little or no cost to you.

(2) Step 2 - Since one of your stated goals is AA miles, make SPG Amex your primary spend card. It's the best yield you can get on a credit card for AA miles. Worst case - small batches - you get true 1:1 with no transaction fees. Best case - what you'll hear a lot of FTers talk about, is that you get 1.25 AA per $1 spent when you convert 20,000 SPG at a time. And you have flexibility to convert to any number of other airline partners. Or...best yet...you keep the points for free hotel stays, where it's easy to get $0.03 in real value per point.

(3) Step 3 - Junk the Citibank AA card. Too much money to be spending on a card that has poor yield and little flexibility. Only exception would be they offer you a retention bonus (e.g., 5,000 AA miles) and you really need the miles more than you need the $85. FF miles might be worth two cents each if you're getting on an airplane tomorrow using the last FF award at your disposal. But if you have 200k sitting there and no imminent plan to redeem them, don't take cash out of your investments and burn it on FF miles.

(4) Step 4 - If you rent a bunch of cars every year - get Diner's. The rewards are far inferior to SPG Amex, but they do hook you up with primary rental insurance. SPG Amex (and most other cards) gives you secondary insurance - they require you to make a claim against your own policy first, then Amex will pay 2nd if needed. With Diner's, your first call is to them - your own insurance company is not involved. To some folks, that is worth $95. It was to me for a few years, but I don't rent quite like I used to, so I dropped Diner's Club.

At this point, the only three credit cards in my wallet are the three hotel cards. 95+% of my spending goes through SPG Amex, with MR Visa getting the rare purchase that wouldn't take Amex. (Always very small mom&pop type purchases - everybody else takes Amex these days.) MR Visa is suboptimal as a general-purchase rewards card goes, but we're talking very small-time volume, so it's not worth the time & effort of getting a gasoline rebate card to stuff in there.