We've been asking ourselves this question several times, and came to conclusion that it really depends. The new generation latex paints are very good, plus there are some hybrid products, looking almost like the old oil paints, but drying much faster.
Working on the trim, our personal favourite was always the real old school oil. The pros of it: very smooth product, levelling long after application, and making the surface almost mirror-like, deep rich colours, and much higher durability comparing to latex. Cons: it's hard to buy oil paint these days (only contractors can do it), long drying time (about 4 hours), heavy smell, yellowing of the white colour over time. Whether you choose latex, or oil, we offer application of either, and will make sure this will work around your schedule and lifetime.