I picked up a no name generic CCTV lens for like $15 online. It's 25mm f1.4. It's similar to this this. I absolutely love it.

It's a piece of junk, the focal ring sticks and is tricky as shit to lose. It's hard to work fast with and it's only sharp in the center of the lens in the right conditions. The apeture is smooth/declicked but you basically have to be wide open or just barely stopped down otherwise you get some harsh vignetting (not the aesthetically pleasing kind).

The bokeh is beautiful tho, it's got this swirly, anamorphic-esque, tilt shift look to it. It flares up nice if the light hits it right and has a natural soft vignette.

off hand I have these two pics that show it off, but it's fairly mild in these examples.

for $15 it's capable of a lot of interesting looks. For contact that's cheaper than lomo/toy lenses. I've seen similar images with the LensBaby trio but that's like $300 and doesn't work well on M43