I don't like MAC polish, as far as application and wearing time it just doesn't hold up.
OPI is unquestionably the best of the three as far as formula goes, it is easy to apply and the drying time is awesome. It tends to chip a bit on me, but with my current manicure routine it isn't a huge issue because I like to change my polish a lot.
That being said, China Glaze is my favourite of the three. Application can be tricky, expecially because they have been tweaking their formula to get rid of the so called Big 3 chemicals. This leads to slightly goopy polish, and that weird thick and thin at the same time texture. Adding some thinner helps, but it is still a question of getting used to the formula. Drying time is not great, but managable with Seche Vite. With my manicure routine it lasts pretty well, a few chips after several days and thus far I haven't had a huge problem with peeling. The thing that puts them in the forefront for me is the selection of colour, finish, etc. No other easily available line has as many polishes that excite me, and they are more affordable than OPI.
Just for informational purposes, I usually wipe my nails with vinegar to remove oils, do one coat of ChG Calcium Gel Fortifier, one coat of CND Stickey, however many coats of polish are needed, another coat of CND Stickey, and then a coat of Seche Vite. I find this gives me rock hard polish that dries quickly, and doesn't chip or peel (unless I do the dishes without gloves or something like that).