I currently have six credit cards and feel like maybe I could reduce the number.

• a B of A mastercard that I have had in one form or another since 2000, when it was an MBNA University of Illinois MC I signed up for on the quad and got a free t-shirt. It sits in a drawer and I almost never use it. I basically keep it now because it's my oldest card and my only Mastercard. Turns out the gas company will only let me pay by credit card if it's a MasterCard, but I just have them deduct from my checking account anyway. No annual fee. Does charge foreign transaction fees.
• a PenFed cash rewards Visa that I got in 2008. I got it because it pays 5% cash back for gas paid at the pump, but I only rarely drive these days and almost never need to get gas (Mr Gfunk is the main driver and takes the car to the office 1-3x/week). No annual fee, no foreign transaction fees. Low credit limit too, only about $5000.
• an Amex Marriott Bonvoy card that I got in 2004. Used to be the SPG Amex. I keep it in a drawer and use it for Marriott stays and for the free night annually. I think the AF is around $95. No foreign transaction fees.
• a Chase United Explorer card that I mostly use when overseas and for buying plane tickets on UA. $95 annual fee and includes 2 annual UA Club passes, which I generally use. No foreign transaction fees. Open a little over a year, since I moved to Chicago and started flying mainly UA. I wanted the free checked bag and group 2 boarding, but now I'm Silver and get those anyway. Don't know if I will remain Silver, though. And I do like the discount on in flight purchases.
• a Chase Freedom Unlimited. Used to be my daily "personal" card since I can combine UR points with our CSR card and can transfer to a variety of places. No annual fee but does charge foreign transaction fees. Open since 2018 or so, or whenever the SPG Amex got converted to the Marriott one.
• a Chase Sapphire Reserve. This is the card Mr Gfunk and I put all our shared expenses on. When there are enough points available I'll either buy travel on the UR portal or transfer points to partners for hotel stays/mileage award tickets. $550 AF but I feel it's adequately offset by the card's other benefits, what with the $300 travel credit, reimbursement for Global Entry fee, various travel insurances, etc. Open since 2016.

What are peoples' thoughts? Get rid of one or two or just keep them in a drawer like I've been doing? I always pay the full balance every month, so I don't even know what the cards' APRs are, and it doesn't matter to me in any case.

With all due respect, you might be asking these questions in the wrong place. You (only) have 6 cards, barely a blip on the radar for some of us (perhaps overly) enthusiastic points and miles (and credit card and SUB) mongers. Many of us have 20 or 30 open accounts with multiple sock drawered cards.

If your goal is to simplify your life, then yes by all means get rid of 3 or 4 or 5 cards. If your goal is rebates or cashback or enhanced travel via points and miles then the answer is completely different.

Freedom Unlimited is a better card for daily spend than Sapphire Reserve. It earns three points per dollar on dining (same as Reserve), three points per dollar at pharmacies, and 1.5 points per dollar elsewhere versus only one point per dollar with Reserve, and it sounds as if you already know how to Combine points.

I am not sure that you need both the Marriott and United cards, but it may depend on how frequently you travel.

One reason not to get rid of the first card you mentioned:

It's anchoring your "age of credit" on your credit report, because you've had it the longest time (over two decades). "Age of credit" is a factor in your credit score, and the longer the better.

In case you prefer another BofA no-AF card, you could probably convert it to that. Converting a card at the same bank doesn't change the age of the account on your credit report.

And for the no-AF cards you're "sock drawering", remember to use them about once a year at least, because you don't want them cancelled suddenly for inactivity. You want to make the decision on which ones to cancel, not have the banks make arbitrary decisions about that.

To come up with targeted advice, one needs to know more about your spend pattern (how much, in what categories, domestic or foreign), your travel patterns and preferences (which airline, how many flights? Hotel preferences) and your goals (cashback or free travel or luxury travel (J cabin, fancy hotel upgrades).

If simplicity is the primary concern, I don’t know that I would keep the BofA card just because it is the oldest card. The Marriott card is of similar age. And I probably wouldn’t keep the PenFed card either - just $5000 credit line doesn’t seem work it. I might be inclined to close the CSR and replace it with a CSP (new bonus, lower fee).

It's mostly about simplicity I guess.

We spend a fair amount on travel and restaurants. Airline is mostly United and its friends. We take 1-2 international trips a year and probably 3-6 domestic. I'm a bit of a Marriott whore but it's not a hard and fast rule; just where my points and stay history are. I think I'll be lifetime Gold after 70 or so more nights. The main benefit I'm interested in is J travel, along with free travel. I have never gotten a suite at a hotel and don't much care about it.

I'm fine keeping things the way they are. If anything I might just get rid of the PenFed Visa ($5,000 limit) since the only real benefit is 5% cash back on gas paid at the pump and I almost never drive these days so saving maybe a dollar or two a month doesn't really matter.

So many variables. My wife and I were both turned down by Citi recently because we have too much available credit with little use - and we have 9 cards between us. I closed one two weeks ago because it was coming up on the annual fee (and it carried a $17,500 credit limit), and had my credit limit reduced on the other cards so I can try again for the Citi card. I guess if you use the cards a lot it's probably easier to keep more of them on the books. This was a first for us and I'm not happy thinking I'm going to miss the 75,000 AA sign up bonus :-)

Whatever your goals re, I would advise to keep your BofA credit card. It's the oldest credit card among all you have (23 years of credit history) - and it has a significant positive impact on your credit score. Your goals may change in life and if you decide in future that you need a loan (mortgage, auto-loan, etc), you want to make sure you approach a lender with the strongest credit score possible (your credit terms and interest levels will depend on credit score). If you cancel your BofA card, your oldest line of credit will become much younger which may result in a lower credit score. So I'd say - keep at least your BofA credit card.