rokinon/samyang 14mm 2.8 is probably the best choice ( it is also for full frame ) buy a nikon mount if you want a confirmation chip.
tokina is a great lens and on ff could be used as a 16mm. Both have some distortion ( apart from the distortion a wide angle always has but that's a different thing
sigma 8-16 or 12-24mm ( only downside is these are not as fast ) the latter has 2 versions the older one has less distortion and the new one is sharper but more distorted
canon 10-22 mm not so fast but minimal distortion
Always a hard choice but choose any of these and you'll be happy. Most wide angles are good so don't worry. even the tokina 12-24 is great and 12mm on crop is wide enough for most if not all you need
tokina is a great lens and on ff could be used as a 16mm. Both have some distortion ( apart from the distortion a wide angle always has but that's a different thing
sigma 8-16 or 12-24mm ( only downside is these are not as fast ) the latter has 2 versions the older one has less distortion and the new one is sharper but more distorted
canon 10-22 mm not so fast but minimal distortion
Always a hard choice but choose any of these and you'll be happy. Most wide angles are good so don't worry. even the tokina 12-24 is great and 12mm on crop is wide enough for most if not all you need