If you have Pixel that is still supported by Google go with GrapheneOS, if not or don't have/ want Pixel go with iodeOS- for the easy installer and ability to re-lock the bootloader on some devises. e/OS/ is maybe the same but I don't like the interface and I don't need the service from the subscription. If non of the above apply LineageOS (for MicroG) but on some devises you need a PC to update to the next major version, some even require factory reset on every major update. Keep in mind that unlocked bootloader can be very insecure when the device is physically taken by the attacker.

Long-term I used LineageOS (tablet), LineageOS for MicroG and GrapheneOS. When I switch from LineageOS for MicroG to GrapheneOS on my phone noticed that some customisations and quality of life features are missing but the difference isn't huge- like double press power button for the flashlight, coffee toggle and that I can't remove the horizontal line at the bottom of the screen. But in my opinion this is noting conpair to the benefits that GrapheneOS offer- superior security, much many user profiles, faster and consistent updates and the official google camera app if your device is still supported by Google. I think MicroG offers better user experience if you are less knowledgeable about this stuff. But sadly CalyxOS have issues at the moment and that's because I didn't include them previously.