what is the best Wide or Superwide angle

Just like the subject line says. I am in need of a new wide or superwide angle lens. I have been looking at the 8mm fisheye that is out there with the 4/3 mount or evenr the 12-24 f.2.8-3.5 ( I think) but I would like to hear what your favourites wide lens is.

Thanks in advance.

the ef-s 10-22, so about 15-30 for 35mm, or 7.5-15 for 4/3 or mft

The 7-14mm is considered the best by many. But there is no way to attach an ND grad so that leaves the 9-18mm. Personally I would be looking on the used market for a 7-14mm, but that's me.

Reading online alot of people do like the 7-14 but alot prefer the 9-18, maybe it is the cost