Also, I would never include "roll again twice." If I include this, I'm opening up the possibility of any two entries being combined, whether they're compatible or not, and I don't want to slow myself down while I'm drawing up the table with considerations of whether my newest idea will play well with my other ideas should I happen to roll "roll again twice." If a combination of two entries on the table strikes me as a fun idea, I'll add that combination to the list; I have no use for a random re-combiner.
I would never add "GM's Choice" either, but for different reasons. Part of the point of the botch table is to assure the player that he is being treated fairly, even in his moments of misfortune - especially in his moments of misfortune. Introducing an element of choice, even if that choice is only exercised after a particular random result, undermines that aspect of the botch table. By making the results random, I have effectively washed my hands of the player's plight; why would I want a roll of 12 to dirty them again?
(Of course, all this hides the fact that the real GM's Choice is my choice of what goes on the table in the first place. If I'm thirsting for a particular botch, I can make the table shorter to improve my odds, or pad the table with variations on that theme. I wouldn't want to do it too often or too obviously, but I think this is a better solution than putting a wildcard on the botch table.)