I have always been happy with the main player.
Have been running Lineage OS since the days it still was CyanogenMod.

GrapheneOS on devices that can run it, LineageOS on devices that can't.

I'm keeping an eye on AXP.OS since DivestOS has stopped being developed.

That is, of course, if you're only counting Android and not Linux mobile. If you are, then I'd add PostmarketOS to the list, though it's hard to find a device that can be used as a daily driver yet, though the Fairphone 6 is very close.

I use GrapheneOS on my main phone, but I use Evolution X for my second phone, and crDroid for my tablet

Note that only GrapheneOS supports bootloader re-locking tho

Right now? GrapheneOS and I don't think I'll switch to anything else until a phone option outside of big tech emerges.

Favorite of all time was probably Cyanogenmod up to Gingerbread and AOKP for that holo era (ICS, Jellybean, KitKat.)

I think around the Nexus 5, I stopped using custom roms until GrapheneOS.

LineageOS, good enough to degoogle and if it's possible for you to use F-Droid-only apps you are out of the surveillance machinery (with the exception of the TSP if you use a SIM card) and it's a huge step from stock Android in terms of privacy.

A better question is how many are really out there at the moment.

Early 2000s there was so many for any model phone. Now it feels like those are mostly gone and there's only 5-6 left.

LineageOS for me

I like e/os with micro-G

GrapheneOS undisputed #1 for me, but also RestlessOS or LeOS for devices that are only compatible with GSI since those also strip out pings to Google.

LineageOS, mostly due to the fact that it's pretty close to the original vision of AOSP; and my devices do not support Graphene or PostmarketOS, so there are almost no viable alternatives.

GrapheneOS for me.

I did use CRDroid for a few years on a Samsung S4 many years ago.

At the moment I'm using iodeOS

Using Graphene, tempted by Lineage.

I've been thoroughly enjoying e/os in s Fairphone 6.

GrapheneOS is the only one I've used since the bad old days of trying random things posted on forums, and it's excellent.

GrapheneOS - maximum security and privacy for phones and tablets

• More Android apps than on other deGoogled OSs
• Very secure (hack-resistant) if correctly set up and used
• Easy to install to the few phones it accepts (some Google, some Motorola 2027)
• Beginner-hostile, complicated manual setup
• Good website and active forum

Notable mention for the beginner-friendly /e/OS (technically inferior compared to GrapheneOS, installable to more devices).

https://www.quora.com/How-does-Murenas-custom-e-OS-compare-to-Googles-Android/answer/Harri-K-Hiltunen

I haven't tried CalyxOS yet. I had CyanogenMod for a few years before it was LineageOS.

Lineage, by virtue of it being the only one that has a version for my Samsung S10+.

GrapheneOS has best privacy and security, but also has the biggest disadvantage: available only on Google phones. But in 2027 it will be released on Motorola, too.

I've been daily driving GrapheneOS for a while now and I love it (Pixel 9a). Looking forward to seeing what Motorola comes out with that's supported by Graphene in the future.

I've also used iodéOS, CalyxOS, LineageOS and Ubuntu Touch. They're all great, but Ubuntu Touch still isn't ready for daily driving for my own use case.