You don't mention some parameters, like SE/differential, conversion rate, budget, etc.
Maxim do a lot of interesting ADC's. Like the MAX1300/MAX1301 which has a PGA, +/- 12V input range, multi-channel input multiplexor, serial interface.
**broken link removed**
Another option is to find an ADC with an i2c interface, and a PGA with an i2c interface. i2c uses addresses on the chips (usually selectable by a couple of pins to ground or Vcc) so your processor can just send the address on the serial lines - no additional i/o's needed.