Euthanasia is a complicated issue. I read an article that a physician wrote, and he made a very good case for why doctors shouldn't perform euthanasia (basically, conflict of interest.)
If someone makes an informed decision that they want to end their life, and the are incapable of doing it themselves, that's one thing. If the person is unable to communicate, though, it gets more difficult.
Then there's the case of someone in a vegetative state.
I think both sides make a good case on the euthanasia issue.