A biased guide to 35mm SLR systems:
First of all, if It is not listed here, it is shooting fish in a barrel. No matter how good the deal is, if it is not made by one of the main japanese manufacturers, it is either most likely overpriced for your needs, or unreliable (yes, I consider Leica R mount systems overpriced).
Nikon- One of two systems whose old lenses work with current digital cameras. Known for making some of the most famous professional SLR cameras of all time, notably the F and F2. If you buy an F2 (my personal pick), make sure the meter is completely reliable. I will be honest and admit that I am not particularly 'up' on nikon's non-'pro' cameras, although in this day and age, with a few notable exceptions (such as the Pentax K1000) there is no reason not to buy a 'pro' model, regardless of what brand you choose. If you insist on going with a currently manufactured 35mm film SLR with all of the bells and whistles, the F6 is, in my opinion, the only choice. As a rule of thumb, if you are buying manual focus lenses, buy ones that have the word 'Nikkor' written on them. For the majority of the Nikon 'F' mount's existence, Nikkor was the term for their high-end lenses.
Canon- There are two different types- eras, if you will- of canon cameras- the FD mount cameras, and the EF mount cameras. If you are concerned about digital compatibility (and, in my opinion, not concerned about looking like a tourist), the EF mount cameras are a solid way to go, except for the fact that they all rely upon microprocessors instead of gears. If I were to buy a canon camera today (in the interest of full disclosure, I used to be a bigtime canon EF fanboy, I still own an EOS elan IIe), I would buy a canon F1, F1n, or 'new f1' camera. These were the pro models. Many will sing the praises of the AE1 or the T90, but with today's prices, I recommend sticking with the pro models, as they are not that much more expensive. For EF cameras at least, the keyword for buying the best glass is the letter 'L.' I am not sure about the FD mount glass, and if you go with an EF mount camera, L glass will cost you a significant premium. The best cheap EF lens is the 50mm 'plastic fantastic' f/1.8 lens, which costs around 100 bucks, and is capable of producing outstanding photographs.
Olympus- If you are interested in small size, or ease of adjusting shutter speed, it is hard to beat an Olympus system. Instead of having the shutter speed dial on top of the camera body, Olympus cameras have it built in to the lens bayonet mount, on front of the camera. Olympus cameras were not as popular when new as canon, nikon, or pentax, and therefore tend to cost more because of rarity, depending on where you are (see footnote). Zuiko is the keyword for buying olympus lenses, it is the term for their high-end glass.
Minolta- Personally, I am not impressed with anything minolta has ever made in their SLR lines (I do, however, really like the Leica CL). Minolta has always seemed to be the girl at the prom that no one would ask out in the realm of japanese SLR cameras to me, although i am sure there are plenty of people who would disagree with me. If I am not mistaken, some Minolta lenses work with current Sony DSLR cameras, although don't quote me on that, or take the advice to heart, especially since Sony DSLR cameras seem to be the girl at the prom that no one would ask out.
Pentax, manufacturers of the non-pro camera I would most reccommend- Unless you want the amazingly small Pentax MX camera, the best bet here as far as reliability and price is the Pentax K1000. The K1000 is the AK-47 of cameras, indestructible and completely ubiquitous. It, as well as the vast majority of Pentax cameras, use the venerable K mount. This means that most, if not all, Pentax K mount lenses work on the current line of Pentax DSLR cameras. It also means that there are a lot of K mount lenses, such as ricoh lenses (avoid ricoh bodies unless they are in absolute mint condition and cheap, imho) which work on older film Pentax cameras but not the current digital cameras which can be had for a song. If price is your number one concern, a Pentax K1000 with a ricoh 50mm f//1.7 lens is the perfect choice.
Footnote- an important consideration as far as SLR systems go is the following question: "What was popular in my area during the 1980's?". This is a major factor in availability of lenses, bodies, and accessories, as well as a major factor in price in your local shops. For instance, I grew up in East/Central North Carolina, where it seems like no one shot olympus cameras. To that end, It is the last place I would want to buy Olympus gear, because if it is available, it will be priced according to its rarity.
footnote 2- This should be obvious from the choices above, but I highly recommend a fully manual camera. A fully manual camera that gets broken/out of alignment can be repaired a lot more easily and cheaply than an electronic one. Basically, if it has a LCD, don't buy it.
footnote 3- If I have left anything important out, please forgive me, as it is 3 in the morning here and my bedtime is well overdue.