Chic

In no particular order:

Rehaul games so there's a non-flash version of them. Get rid of the least popular games. Get rid of the blatant gambling.
Rehaul ALL the art. One team of artists does this; push for a consistent style. Have a training program in place to get new blood drawing in that style if they don't already do this. For nostalgia's sake, have a theme you have to do a quest for that makes the site look like it did in the early years.
Cheat-proof the site. Find a way to ensure everyone has access to a secret number of rares per week in shops that's only available to them as well as some public rare drops. 

Fix the filtering system; have live mods online 24/7. Combine a few chat boards or get rid of some.
No NeoCash games or events. Keep NeoCash but you're just buying wearables.

End the Obelisk event and start newer, smaller ones around 1-3 times a year. Maybe make some popular ones recurring like the Altador Cup if the players ask for it. There's already a lot of lore to work off of.
Undo all bans. Restore accounts. Blank slate, give rich rewards for telling Neo about the glitches and exploits. 
More stuff outside of the website - merch, video games that are actually good, maybe a cartoon.
Make it a goal in the long run to give every item an actual use. 

So I just tried to log in to old accounts and literally the only ones I have that still exist are the accounts I purchased. Neo banned me for legitimately, finally getting the tree in whack a kass on a new one I made yesterday. I sent them the screenshot and everything

I guess this is it, then. What a shame, as I just recently got back into Neopets.

 

RIP Neocodex.

It's kind of nice to actually be able to restock legitimately again, though