I'm using a text comparison tab for identifying differences in the greek text when I look at certain scriptures:

I use the NA27 because it's the version I use predominately now; Stephens' because I grew up on the KJV and it's the base text for that version; the BYZ because it represents the majority of greek texts and the UBS4 because it's the critical (scholar's) text -- don't really expect it to vary from the NA27 so there might be some redundancy there.
I think I've captured the main lines of greek text by using the representatives above. Any others you'd add to that list? I tried using TENTGM but got some weird results. Thanks in advance for your comments!