Rich, smoky, and tender... ribs are such a fantastic food! My favorite combination is probably 150°F (65°C) for around 18 to 24 hours, it's shreddable but not too fall-apart. Some other popular combinations are 165°F (73.9°C) for 18 to 24 hours or 176°F (80°C) for 12 hours. For a chop-like consistency I generally prefer 140°F (60°C) for 1 to 2 days.
Medium-Rare: 135°F for 1 to 2 Days (57.2ºC)
Medium: 140°F for 1 to 2 Days (60.0ºC)
Well Done: 145°F for 1 to 2 Days (62.8ºC)
Braise-Like
Tender Braise: 150°F for 18 to 36 Hours (65.6ºC)
Firm but Shreddable: 156°F for 18 to 24 Hours (68.9ºC)
More Fall Apart: 165°F for 18 to 24 Hours (73.9ºC)
Really Fall Apart: 176°F for 12 to 18 Hours (80.0ºC)
As long as you have enough space for the water to move around you are all set!