I chose invincibility because realistically, if you were immortal, then life would not only become boring in some cases, but you'd see friends and family grow up and die around you while you lived your own life, and if you were injured severely, you could be living for hundreds or thousands of years with that pain, unless euthanasia or suicide were bearable.
Knowing I had a reasonable life without pain seems much more appealing than having a theoretically infinate life but still be prone to physical pain, as well as emotional suffering.