It depends upon what you are training for. If it is OL, neither is better, you have to be good at both.
From a general training standpoint both have their merits. Both require coordination, strength, power. Cleans will use a heavier weight, a snatch is moved faster.
The snatch requires greater shoulder flexibility, the clean requires greater wrist and elbow flexibility.
If you are doing a full snatch and a full clean both are good. The hip flexibility required is higher for the snatch.
From a sports training standpoint neither is better. I know a lot of people use cleans like crazy, you can get as much or more power production out of pulls.
So, I suppose the real answer is, cleans are sometimes better for some people during certain times in their training, snatches are better for some people during certain times in their training. Sometimes neither lift is the best. If an OL both are equally important.