Depends on whether you need some specific form factor.
If you need to replace those tiny ESP-01 boards, LilyGo does have a "form factor compatible" T-01C3 which is using an ESP32-C3
N.B. I use "ESP32-classic" to refer to the good old ESP32, thus no -C, -S or other variant.
Not sure if "classic" is used anywhere else, so no need to look for "classic" on sites like Ali Express
If you have the option, I would suggest to go for boards with 16M of flash.
The ESP32-S3 is by far the most capable as it has lots of IO and is quite fast.
The ESP32-C3 can be had in a very tiny form factor and still has all its usable pins made available.
The ESP32-C2 is used in some of-the-shelve units, so that's why I added support for it.
But I wouldn't use it for anything else as it is a limited chip in lots of ways.
The ESP32-C6 does have WiFi-6 support, but other than that it isn't (yet) much different from the -C3.
It might be useful later when we add "threads", or Zigbee support. But I'm not convinced it is really usable with both Zigbee and WiFi at the same time.
ESP32-S2 is a bit of a strange "inbetween" chip.
It does work fine, it may feel more 'snappy' compared to the other ESP32-variants (except -S3) and it does have more GPIO pins compared to other boards (except the -S3 which has more pins)
But it feels like it is a bit odd in several interfaces.
Also there are some purple boards sold with the S2 which are really a hit-or-miss regarding WiFi stability.
IMHO, ESP32-S2 is not worth it anymore now we have the -S3.
And last-but-not-least... the "ESP32-classic" is still a viable option.
Just make sure to go for 16M flash as it allows to install the "max" builds which contain all plugins and controllers.