I trade cd-r preferably tdk or sony.  That's what I normally use, but anything is fine as long as it is good quality and not from one of those 5000 discs for three dollars type of deals.  I tend to play by the same rules as everyone:

1. good discs

2. i prefer discs without writing in sleeves. i prefer writing to be on the sleeve or on a post it or something.

3. i use exact audio and slow burn speed and i hope you do too.

4. please no discs sourced from mp3.

5. i don't like track at once gaps either, if your disc has gaps please let me know beforehand.