Not a port or a remake, but something that was designed for and released on a handheld. I don't really have the Switch in mind when asking this question, but I suppose there's not really a good reason for excluding it.
For my part, I would go with Advance Wars: Dual Strike. It's been years now since I've played it, but I remember it as the peak of the addictive Advance Wars formula, a game which made good use of the touch screen and unique layout of the DS. The tag-team component, beyond justifying the DS acronym, allowed for some really cool combinations of leader abilities and powers.
For my part, I would go with Advance Wars: Dual Strike. It's been years now since I've played it, but I remember it as the peak of the addictive Advance Wars formula, a game which made good use of the touch screen and unique layout of the DS. The tag-team component, beyond justifying the DS acronym, allowed for some really cool combinations of leader abilities and powers.