What you prefer in a re-issue?

My choices:

* Bonus tracks (live, demo, rehearsal, re-recording, covers etc etc .. but no interviews... I HATE audio interviews in CD's haha)

* linear notes about the recording process, about the songs

* remaster (if possible)

Visually I want the same artwork (unless the band REALLY hates the original), same booklet design with the possible exception of liner notes and LYRICS.  I prefer jewel cases too.

Remaster if necessary.

Either no bonus tracks at all or a whole 2nd disc of bonus material.  If I have the original I won't buy an album twice to get 1-2 extra songs.  There are favorite bands I will never get to hear ALL of their material because an album's worth of bonus tracks are spread out over several reissues.  This means you Mortification and Disciple.  Make it worth my money to buy it again.

I buy reissues I already have regardless of the above preferences if either: 1) I'm upgrading a format (cassette to CD like the Roxx Recon or Deliverance - Stay of Execution reissues), or 2) I get a TON of bonus material (Circle of Dust, 77's - Sticks and Stones, etc.).

Remastering.  Bonus tracks that may be newly recorded or were cut in the studio.  The live and demo tracks rarely are listenable to me due to poor overall sound quality.  I rarely play those when they are included.

For them not to remaster and ruin the tracks. I hate the stupid loudness war they have now. Megadeth being the worst for this.
But yeah, I hope they have a bonus track or something, I don't know.

Some albums needed a remaster, like just about everything on Pure Metal, but I hate the loudness wars too. Bonus songs are almost a must.

-Remaster! 
-Bonus tracks are cool if they are decent enough.  Like Alldat said it seems a lot of the live and demo tracks are nearly unlistenable on several the reissues I own (at least to me).
-Extensive liner notes are also very cool, especially a write-up about the history of the band during the era, writing/recording process, etc.