I love my Nikomat/Nikkormat bodies for really tough, inexpensive mechanical bodies. For around $75, you can get a nice FT2 or FT3 model. If you need modern, I'd say get a clean F100 for under $200. They've got all the features you're likely to want. For around $125, and fewer features than the F100, but not as spartan as the Nikomat, the FE2 and FM2 are hard to beat. My 2¢.