The Adafruit ADS122C04 24-Bit ADC with 4 Channel 2-kSPS is an excellent way to take very high-precision measurements of single-ended or differential analog signals over I2C. Most 24-bit ADCs are found on strain-gauge sensors like the NAU7802 and don't have high speeds or configurations. And most fast-ish I2C ADCs like the ADS1115 top out at 16 bits. The ADS122C04 is a bit more expensive than either but it's one of the few ADCs we've seen that gives you up to 2000 samples-per-second (on one channel) at 24-bit resolution.