Having played and beat both, I would personally take Dragon Quest.. It was just such a supremely beautiful and well made game, a pleasure to play from beginning to end, and I love the whole old school mechanics ripped from the 80s/early 90s meets game with modern graphics & QoL vibe.
Xenoblade 2 is also great, and its certainly a more ambitious game, and has a lot more going on in terms of its open world, realtime combat systems with tons of layers, depth of story, and various systems in play- parts of it definintely soars, but there is also some clunk to it. (performance issues, its mindboggling use of a gacha system when it comes to developing your party and its abilities (which later in the game play into abilities needed traversal, so its not like you can skip this system, terrible mapping system, etc.