On the international level, there's simply no comparison between Bale and Giggs.
Giggs - 64 caps, 12 goals. Bale - 109 caps, 41 goals.
Giggs never appeared in a friendly for Wales, you can't keep Bale away from the national team.
Giggs was one of the best players of his generation at club level, but as an international he was merely pretty good.
Let's not forget that he once deliberately got himself sent off so that he wouldn't have to travel to Moldova or somewhere.
Bale has been the key player for Wales for over ten years; without him, we'd never have reached the semifinal of Euro 2016 nor have qualified for the present World Cup.
Rush - yeas, a great player and great goalscorer, but Bale has contributed more to Wales, though Rush would be one of the first names in any "all-time" Wales team.