Let’s hit the wayback machine. I don’t just want a ding, I want a lot more. I want an entire celebration system. No more of this “little graphic and audio effect” nonsense. Give me fireworks that shoot 100 meters into the sky along with Ode to Joy, as if this were Peggle. Send a message to my group, the zone, and my guild. Keep a permanent journal on my character that commemorates the moment with a time stamp, what put me over the edge, and a note about how awesome I am. Then have the nearest NPC send me a letter in the mail reminding me of how awesome I am, for the next time I hit a mailbox. And think of some more ways that the game can tell me just how great it is that I leveled. If I hit the level cap, have a statue that looks like me (at least when seen from my client). Ooh, better: have two lines of them along the path to the main castle (or whatever), with the number of statues set to the number of characters you can have on a server. If you cap all your characters, they all see lines of YOU YOU YOU OH SO AWESOME as you ride into the castle.
Also, give me a menu option so I can toggle all that crap off, at least other people’s meaningless ding spam. I mean really, this is all about me, not them.
That statue idea isn’t half bad, really.