Canon cameras have a relatively short sensor to flange distance, so there are tons of old lenses that can be adapted. There is a whole section on FredMiranda.com on alt lenses. There are also flickr groups as well as forums dedicated to manual focus. You should be able to find lots of opinions and sample pictures out there. Contax/Zeiss lenses are popular as well as Leica R. These aren't really budget though (generally speaking). I really like the Olympus OM series lenses. They are tiny, light and have pretty decent quality. A lot of them can be found under $100. The ones with better reputations can be a little more expensive. I've been able to get ahold of a lot of the Olympus OM f/2 lenses for around $200, and they make pretty nice pictures. Also, it's my understanding that with video, since you're recording at a resolution of 1920x1080, sharpness isn't such a big deal. The samyangs are pretty nice too. I have the 35, and it takes great pictures. It's huge though.