If you got a ring stuck on your finger, and finger is swollen, what is the best way to get the ring off?

Several. If you have done all that your can with greasing agents (crisco works well), have tried ice, and it just will not come off, then there is a way to wrap the finger from distal to proximal and the pass the end under the ring and reverse the process. This works often. If you cannot removed the ring and there is danger of the ring remaining, then you will have to have it cut off at er or elsewhere.
Ring cutter. If it appears that the finger is so swollen that it would be impossible to remove the ring, the ring will then need to be cut off. In an emergency, the emergency department of any hospital will have this capability. Many doctor's offices will also have a ring cutter.