Often described (as many other cameras are) as the "poor man's Leica", the Canon Canonet QL17 is a brilliant rangefinder at a fraction of the cost of most other rangefinders. It sports a crystal clear, tack sharp, f1.7 45mm lens that accurately captures colors as well as all the gradients between black and white. Produced in the mid-1960s and sturdily built, many excellent examples of this camera and later versions can be found on ebay for a steal. Due to age, the light seals need to replaced but this can be done by most camera enthusiasts with a sheet of black foamy, x-acto knife, and some adhesive. There are several website that offer instructions on how to replace the seals simply by plugging Canonet QL17 into a search engine.
The Canonet QL17 features a beautiful 45mm f1.7 lens constructed of 6 elements in 5 groups. According to the Canon Museum website the camera has a "coincidence rangefinder integrated with reversed Galilean viewfinder..." offering "Automatic parallax correction with projected frames and marked finder" at 0.7x magnification. What this means is that it is easy to get a precise focus on your subject and see precisely what will come out on your film. It is important to make your first attempts to focus this lens outside in bright sunlight to get the hang of the focusing lever. Sunlight shows the greatest distinction between what is in focus and out of focus. Once you get the hang of it, it is easy to focus anywhere.
The QL in its name refers to Canon's quick loading system. You do not have to the thread the film's leader into a spool. You simply pull it out and place it on the take-up spool and close the back. The film catches on its own every time. The camera has match needle metering system which easily shows whether the exposure is correct. There is a lot of latitude with a metering range of EV 2.5-19. The lens is very fast at f1.7 to f16, while the shutter speeds range from 4 seconds to 1/500th, and a bulb setting. The automatic metering with its Electronic Eye (EE) can be shut off to allow manual exposure. It also has a 10 second timer and a remote line can be screwed into the firing button to reduce the possibility of camera shake when using a tripod. Films ranging from ISO 25 to 400 can be used. From my experience 50 to 100 ISO is best. ISO 400 is impossible to use in bright sunlight even at f16 at 1/500th shutter speed! Canon made a Canolite D flash for its rangefinders in the Canonet series. Other flashes that can be manually set are usable with the camera too. The one potential downside is that the meter required a 1.3 volt MP Mercury cell which is no longer available in the US. My guess is that since Europe and other parts of the world are "greener" than us, the batteries are impossible to find. There are two options: 1) use a 1.3 v Wein zinc air cell which mimics the mercury cell, or 2) use a 1.5 v alkaline cell and and know that the metering will be off a bit. The zinc air cells can be bought at some camera stores or ordered online. They are used primarily in hearing aids. Actually there is a third possibility which is to spend a lot of money to have a camera repair shop adjust the meter to use 1.5 volt batteries. The zinc air cells are about $8US.
I should add that this rangefinder is, of course, a 35mm camera. It shoots color and black and white film, positve and negative, with equal proficiency. I will often use slide film because the meter is dead on and the focusing so easy that perfect shots are a near certainty. While I have never owned a Leica I have used other rangefinders and for the money the Canon Canonet QL17 cannot be beat. Some like the GIII version of this camera which was made later. I prefer the original. Also be careful: a lot Canonet 1.9s are out there for purchase, they are cheaper, but the lens is not as good. If you decide to buy one you should be able to get a copy of the manual off the internet. I think the manual is necessary since the lens has a lot of numbers on it, on four different movable dials. it looks confusing at first but if you have the manual your wind up saying "oh that makes sense" to yourself a lot. A truly magnificent rangefinder!