I currently have 21 cards including one AU card that is not in my siggy and that I may not retain long term. I've had credit cards for over 35 years and this is BY FAR the most cards I've ever had at one time. Over time however, I've probably closed (or had closed) many more total cards than I have now for various reasons. I have more cards now because I started redefining my card lineup a few years ago and got on My Fico, where I got a little carried away by the MY FICO EFFECT. Lol 
My total credit limits are $588K, which is also BY FAR the largest in my life and honestly much more than I really need.
I've experienced 21 cards and decided that even though that pales in comparison to some of our other members, it's more than I want to manage for the long term. My goal has been to get very high limits with very few cards, and I've generally achieved that so far. My average limit is about $28K but I want to drive it even higher. While I do plan to add a few cards, I also plan to consolidate or close others so that in the end, I'll have no more than 12-15 cards. Maybe less.
I toyed with the idea of as little as three very-high limit cards by consolidating what I could on some of my best/favorite cards and closing others. I could do it tomorrow if I wanted to, but I don't really want to pare down to that degree. I like the lender diversity, among other things, including the ability to get even better rewards with a few more cards. 
My fewest high-limit card lineup would be:
American Express Gold (NPSL and $18K Pay-Over-Time)
- 4x MRs on Dining and Groceries (Uncapped / $25K annually)
- 3x MRs on Flights (Uncapped)
- 1x MRs on Everything Else
- Premium Perks and AF credits
Chase Sapphire Reserve Visa Infinite ($127.4K CL)
- 3x URs on Dining and Travel (Uncapped)
- 1x UR on Everything else
- Rewards with 50% or higher for Chase portal travel redemption or transfer to partners.
- Premium Perks and credits
Bank Of America Premium Rewards Visa Signature ($99.9K CL)
- With Preferred Rewards Platinum Honors ....
- 3.5% uncapped cash back on dining and travel
- 2.625% on everything else
If I wanted to add in a Mastercard and Discover for more network Flexibility, I could add my:
Goldman Sachs Apple Mastercard ($30K)
- 3% at Apple, Walgreen's, other selected retailers
- 2% anywhere with Apple Pay
- 1% elsewhere
Discover IT ($50K)
- 5% on rotating categories
- 1% anything else
While it's a very clean lineup, and I have to admit it's quite tempting, I doubt that I would ever take things to that degree slimming down.
@GatorGuy wrote:
@Citylights18 wrote:I have 12 credit cards but out of that I only run a balance on 5 of them. TCL across the 12 is $222,600.
4 of them I PIF every month, the other one is a store card that I have a 0% APR promotion.
I pay $389 in AF across all that cards but that includes:
-Amazon Prime yearly membership ($119)
-Free night at Hyatt ($150-$350)
-Uber Eats pass ($120)
-AMEX offers ($50-$100)
-Chase offers ($50-$100)
-Loungebuddy ($100)
Conservatively at least $589 of direct perks against the $389 in AF that I pay.
What card gives you an Amazon yearly membership?
This year NFCU Flagship reimbursed membership if you paid with the card.
@RT209 wrote:How many is too much? I have a total of 14 cards, totaling up to almost 130K in credit limit between all cards. My utilization all together is only around 4%. Obviously, I don't need any more cards, but the urge to grab more utilization when i can gets me every time. Haha.
My Sig tells no lies 
@Anonymous wrote:@Aim_High
You may want to add into your mix aesthetics! Keep some eye appeal?
Thanks @Anonymous but not sure: do you mean more colors for eye appeal or just not so few cards?! 
Those five from the aesthetics standpoint would give me a gold, blue, grey, white, and garnet so it would seem a little more mixture than my previous color pallette of blue and silver/grey!