My favorite lens during the last ten years of my career as a Picture Editor was the Canon EF 14mm f/2.8 L lens.
The 14mm was big, heavy and ULTRA WIDE in coverage! It also has a big price tag to match! It can set you back for NZ$ 3,000 a piece!
I love the elongated perspective of this ultra wide lens and with it, even a slight difference in shooting angle or position will cause a great difference in how the subject appears!
I wrote about the lens here.
After leaving the paper I cannot afford that expensive chunk of glass, I had to look for a cheaper alternative for my ultra-wide addiction!
I decided on the very compact Canon EF 15mm fisheye lens. There are some good reasons behind it ;)
It is small, it is relatively cheap compare to a 14mm ultra-wide. At NZ$1,309.00 (latest 2011 price) it can give wider coverage than a 14mm, especially if you are using a APS-C size DSLR.
If you are a lucky owner of a full-frame DSLR, this little beauty will reward you with a angle-of-view of 180 degrees!