micro processor

If you want everything built into the chip, then what you're probably looking for is not a microprocessor, but a microcontroller.

Microchip PICs are the most well known, and used by experimenters everywhere. The 16F84 probably has the most stuff (compilers, homemade programmers, etc) available for it, but it's getting pretty old and is also more expensive than newer PICs Microchip have developed since. As for Motorola, I think they also make loads of microcontrollers, but I don't think there's anywhere near as much information about them in the hobbyist business - they seem to be the exclusive domain of the Big Boys. For hobbyists, PICs are probably the best bet. In fact, I think just recently Microchip have started producing a new range of chips with extra motor control circuits built in, but even the old ones often have things like PWM outputs and analogue inputs, useful for driving and getting feedback from all kinds of motors.

Tom

I recommend PIC microcontrollers. Most PICs have 2 channels of hardware PWM. That means that you don't have to generate the PWM with software. Just set the freq and duty cycle and out comes the signal. No fuss, no muss, no interrupts. The 68HC11 does not have hardware PWM :-(. Check out

The motor driver (the H-bridge) is not part of the chip, of course. You wouldn't want it to be for most applications. You can choose the H-bridge separately to fit your needs (L293, L298, LMD18201 (my favorite), etc.)

BRW

I wouldn't discount the motorola chips. Try the HCS12 dedicated PWM, Timer input output channels, 16 bit ADC, 2 channel DAC, I2C bus hardware module. Depends on how complicated the thing your trying to do is and what functionality you need.