HAL has entertainment and shows, but it isn't a strong point for them. Standard things and nothing new or innovative. Lounge singers, a band or two, a 'big show' that is a musical revue.
But then since an Alaska cruise is really all about seeing that state and it's waterways, and the ship is just a conveyance and hotel, you should look more at the ports you want to see and not so much which ship you take. In the Caribbean the ship can be the destination. In Alaska, it isn't.