Originally posted by Jeff C also note that i need it to fit onto my pentax me super
I agree with Steve; The Zenitar K is easy to find, and quite good for the money (especially stopped down to f/4.0-f/5.6). You get a 180-degree diagonal fisheye on film, and a fishy-wide-angle on digital.
Other options in the 16mm range are:
Sigma 16/2.8 manual focus
Sigma 16/2.8 autofocus
Pentax K 17/4 (hard to find)
Pentax A 16/2.8 (impossible to find)
M42-mount Pentax 17/4 Fish-Eye Takumar (in Super and S-M-C versions) -- this is the very good looking lens shown in my avatar
If you ultimately decide you want to go fishier, you can always add on the DA 10-17 fisheye or an 8mm Sigma or Peleng.
EDIT: I just read your profile and realized that you're film-
only: in this case forget about the DA10-17.