"Best Laker Ever" is too broad of a statement.
"Best" can be sub-categorized either by stats, championships, popularity, etc...
IMO, bringing the championship trophy to the city is what I consider to be the best athlete of that team in any decade, followed by individual stats..
So if Kobe gets more rings than Magic (who has 5) or Kareem (who has 6), then I will consider him the best Laker ever..
If Kobe doesn't win anymore championships and retires with 5 rings, then Magic or Kareem gets my nod over him.