Cheapest Option
Estimated Cost: 50-75€
This option will give you the bare essentials in terms of features for scanning 35mm at good quality, though it will struggle to pull out everything that medium format has. That said, these will give very good scans, even though the older interfaces and some lacking features make them a bit more fiddly to work with.
Pros
'Modern' sensors
The sensors that came with these cameras came out around 2010, when the technology they use - CMOS - started improving dramatically and got control over the, up until then, bad signal to noise ratio. This allows these cameras to provide good results when scanning negative film - which has a lower density range - though they will not be able to pull out as much detail from the shadows of slide film as more modern sensors can.
Full manual control
There are cheaper cameras than these cameras but many of them point-and-shoots or in other ways 'dumbed' down. The cameras recommended here all have manual settings, so you can get full control over the exposure of your scan. This is important, particularly for more challenging scenes or if you want to scan a whole roll on the same exposure setting (this is recommended in some cases - see the Technique Guide for more).
Decent image preview
The mirrorless alternatives mentioned here have live image preview on the back of the cameras, as a default. The DSLRs, you will have to set to live-view, which will make them eat battery. For this reason, and for a few other reasons, the NEX-3 and NEX-C3 are preferred over the DSLRs.
Mirrorless: Easy to adapt lenses to
This only applies to the two first cameras (below) as they are mirrorless cameras and therefore have a short flange distance. Read more about adapting lenses HERE.
Cons
Quite old (10 years)
The sensors are not as good at handling very deep shadows (under-exposed areas) as modern sensors. This is most important when scanning slide film - so if you do, you might want to consider a more modern sensor.
No electronic shutter (a bit more vibration)
None of these cameras have a pure electronic shutter. The mirrorless cameras have a shutter the makes less vibration, but they still have moving mechanical parts. Consider going for a higher-end camera if you need even more detail your images. The DSLRs will cause more vibration than the mirrorless.
Low resolution for medium format
The resolution is below our recommended 16MP for medium format. If you scan a lot of medium format, we recommend a camera with a higher MP sensor.
Harder to focus (worse screens)
The two mirrorless cameras in this category are easier to focus than the last three because they are made to use the screen for focusing and viewing your image, unlike the three DSLRs. However, all cameras suffer from older screens that are harder the focus and harder to frame with.
Suggested Cameras
In order of priority
Sony Nex-C3 - Sony Nex-3 - Sony Nex-3N - Canon 500D - Nikon D3000 - Canon 450D
The three first cameras are much preferred over the last three, for they are mirrorless cameras, which are much more suited for camera scanning. However, the latter three are cheaper and will produce somewhat similar results, though the ergonomics are not as good and the ability to adapt lenses will be more limited.