Sad confession: I'm a bit of a flag geek. So the lack of a flag for Northern Ireland bugs me. This post is basically an excuse for me to share this design I did in a fit of 'putting-off-work' a couple of years ago, but I'll also ask: what do other people think a flag of Northern Ireland should be? If not my design below I'd personally support the plain St. Patrick Saltire - it lacks potentially sectarian imagery like the hand and crown whilst expressing positive unionism via being the flag that represents Ireland on the union jack.
However, combining elements of the old Ulster Banner and the saltire looks quite good, IMO.
EDIT: I submitted this design to a facebook group about the NI flag a couple of years ago, and they made a slightly different version.