I always use the original date of release of the album in the year field.If it's only one or two albums where I have both the original and remastered, then I add "Remaster" to the end of the album title, e.g. "Rocket to Russia (2001 Remaster)".
EDIT: Sorry, didn't realise this thread was almost a year old as it was still on page 1 of the "General Music Discussion" forum!
REISSUE where i put "Remastered" or "Reissue" (if its rereleased, with bonus, different tracks or whatever but not remastered)
So yeah, I've let go of the obsessive collector mentality. I stopped obsessing and decided to just enjoy the music rather than any specific recordings or editions :-)
Personally, I think it deserves it's own tag field, containg the year. label, and catalogue number. And a another field for the mastering engineer.
The ID3v2 spec differentiates between TYER (year) and TORY (original release year), but, unsurprisingly, is clear as mud...
%date% - %album%[ '('%edition%')']