Achievements from only playing Vanilla, such as PvP titles. I only got Sergeant because right before they removed the PvP titles, I lost Stone Guard :[
Show 'em your payment history.
Old School Ride when the achievement system was implemented.
You could mention the Nightmare Drakes ... only vanilla people know what you're talking about. :P (Most vanilla players probably even forgot all about them).
So, anything else apart from PvP FoS, Original epic mounts and BC intro event gear? (and maybe corrupted Ashbringer?)
Only way to tell for me is my payment history. My main has switched servers and names a couple of times so warcraftrealms can't pull it up.
Originally Posted by High Overlord Saurfangi7-860 @2.8GHz | Radeon HD 7770 | 8GB DDR3-1333MHz | Corsair CX 430W |