Search Analog Devices, Linear Tech, Crystal,TI as these companies have a variey of products.

Personally i've used AD7730 and ADuc 824/834 parts for strain gauge measurement. Noise is a big issue and I only get about 14bits of useful readings. TI have a good app note on using their msc1210 for weigh scale measurements where noise is discussed in length.

Most people use 24bit adc's for the dynamic range rather than the specific accuracy - also remember that 24bit adc's are normally sigma-delta conversion and there is a few things to be aware of. They are usually quite slow - my app samples at 20hz. Read the spec sheets carefully before making a decision and read the app notes on layout, noise, component selection etc.

Some of these parts can measure you breathing! Thermal and piezoelectric effects also come into play.

The exact part you choose is dependant on many factors - there is no 'best' part - in future it is probably best you do some groundwork before asking such an open question as what may be good for me is not necesarily good for anyone else.