I'm interested in credit cards, cashback, travel points and the like. I find it very fascinating that there are so many credit cards out there. All of them seem to have their own perks, benefits, and privileges. Which credit cards do you use?

I personally use American Express and have a backup VISA and Discover. AMEX just provides a lot of cool things that add up over time like their FHR program for travel. It's nice getting a late check out and a credit to use at the hotel bar and breakfast everyday. The wife and I travel about 4-5 times a year and the benefits really add up, even when you subtract the annual fee :D

My main 3 are my Bank of America card gives me 3% cash back on all online purchases, that is my main online credit card. My US Bank card gives me 5% back on my phone bill and 5% back on a category of my choice which I usually have on electronic stores like Best Buy. Target Card of course for 5% off on all Target purchases.

I use all four of those for various purposes. Mostly visa and discover for personal stuff. Mostly Amex, Visa, and MasterCard for business.

I have a 2% cash back (on everything) MC I use for most things and a basic no fee VISA for places that don't take MC. Both set to auto pay in full each month, of course. In the future I may get another for business and/or rewards.

A bit over ten years ago I was broke with ruined credit. It felt pretty good when I finally broke 800. 

I have 10 credit cards

I have multiplier points on all of them except for the shared credit union card. 

My highest credit limit for a card is $20,500 and lowest is $3,900.

Chase Visa - for subscriptions and paying for tolls

Amazon Visa - for Amazon shopping since 95% of my shopping for non-groceries is from Amazon

Citi Mastercard - for digital purchases such as games, TV shows, movies in moviesanywhere format, etc

Discover Mastercard - for food outings right now - usually use this as my balance transfer card, alternate between this and BoA

Bank of America Visa - using it as my balance transfer card right now - usually use this for food outings but alternate between this and Discover

American Express card - my burner card, if I go to a new place or shop online to a place I'm not familiar with, I use this instead of other cards

Costco Mastercard - only use it for Costco shopping (since its near my home) and I only pump gas at Costco for my cars

Best Buy Visa - only use it for purchases at Best Buy even though I could use it outside, I only use it for large appliances purchases like Washing machines, dryers, computers, etc.

Macys AMEX - only use it for Macys shopping in store or online , usually use it holidays like Christmas, black friday, July 4, etc

Shared Credit Union card with wife - just an extra card if needed to split on purchases.

My wife uses her cards for shopping groceries

That's an incredible credit mix and congrats on that over 800 score. Mine was 815 or so before I took on a new loan for new siding, gutters, and front door. Then I opened a couple more credit cards that were 0% for 12 months. 

My cards:

American Express Platinum - for large purchases and vacations 895 AF

American Express Blue Cash Everyday - 3% grocery, gas, online retail, no annual fee

American Express Blue Cash Preferred - 6% grocery and streaming, 3% transit and gas 95USD AF

Discover It card -  2% grocery/gas, 1% everything else (I don't really use this one anymore)

Fidelity VISA - 2% everything, cashback deposited to Fidelity cash account

Credit Union MasterCard - My first ever credit card, no usable perks

My highest limit is 25,800. I think my lowest is 10k.

I have a re:member card, I use for car rentals when I go to visit my family and friends back home. I got mine right around the time my last lease expired and I knew I won't be getting another car. With the built-in extra insurance in case of damages or injury, it's easily the best credit-card for this purpose around here. For other purchases, I don't use credit, but I have a Revolut account for international transfers and investments (there's so much less pain that the uptight banking system and actors here). Almost every day-to-day purchase or order is made with a regular debit card, it's simple and easy to manage. I can't imagine having to keep track of several lines of credit in addition to five accounts and three employers.