Not that I play any more but the things I miss that are now gone:
Wormhole space as it was in the first couple of years - still somewhat unknown and more of a barren wasteland between the bits where people had scratched out an existence giving a good balance of danger and potential.
Rattlesnake/Gila as they were before the drone changes, etc.
The old Kronos with 90% webs - though I actually came to like the Bastion functionality I still wish they’d preserved the old marauders as well.
My old Thanatos with the massive capital changes around 2014 - one of the reasons I quit really as it felt like the loss of a character - I’d been dragging it around behind me for around 2 years or so using it for storage, support, PVE, emergency bailout, etc. and with the changes that was all gone.
Strategic cruisers as they used to be - sure in some cases a bit overpowered but they were fun, massive potential for innovation and actually worth putting some blinged up modules on which gave a bit of a goal to playing to be able to afford that, etc. and made them more interesting to kill because someone might have blinged their one out.
Things I don’t miss:
People complaining about AFK cloakies 