normal = just the game
limited = game in a metal case with a making of dvd
Legendary = collectors edition inside a limited edition Spartan helmet with an extra disc containing all the cutscenes from halo 1 and 2 in High Def and some machinima interviews.
Please get it right. I admin a large-ish online retailers forum and the amount of people getting confused over the editions is largely attributed to people giving the wrong names
It goes:-
Normal
Collectors (NOT Limited!)
Legendary
There is NO Limited edition, unless you class the Legendary Edition as "Limited" as it is manufacturer limited.