I have not posted in this part of the forum yet but I might do so from now on.
I have tried loads of ultra wide lenses and depending on what you want to do with it I would recommend the 10.6 fish eye. marry that with the 18-200 and you have the best travel kit going around. We traveled for 4 months in europe with just those lenses and I needed nothing more.
If you do need 2.8 at the wide end and a zoom then go for the 14-24 it is one of the most highly regarded lenses to the point that canon owners get adapters to use that lens on their bodies.
Here is an example of the fun you can have with a fish eye
https://www.aulro.com/afvb/images/im...11/07/1253.jpg
