MAtech rear & KAK front, if you can warrant spending the money. Amazingly strong & durable. Tool less adjustment & graduated to 600yds (pretty much dead nuts on, if zeroed at 50/200 with 62gn ammo)
Only irons I've used on a personal AR that wasn't an A2 is the Magpul Pro Offsets. They were a door prize at a local 3-gun match. They fold really flat and the rear sight has both a wide and fine iris. I haven't used them much but they're out of the way enough that I haven't seen a reason to take them off.