Well, GTA like most people said. Other than that, nothing else. GTA sells just about anywhere, any other existing franchise that fits within the genre would be needlessly impactful in gaining traction, but would not a greatly profitable outcome. Like DOOM.
Nintendo just need to put out their Animal Crossing, 2D Mario/Mario Maker, and thereafter work on new IPs and they've got all their heavy sales hitters out of the way. Then leave it to Japanese third-party support and indies, and see how goes. We'll probably see 3DS-level sales at peak if Nintendo plays their cards right. The Switch can only do so much to maintain relevance in this generation, since a lot of the multiplats that have been announced so far are missing the platform. It would be ideal if Nintendo could make their hardware more attractive to newer developers and if they see success and expand, there could be more ambitious titles for the system.
I for one, do not mind this. It's unrealistic to suggest that Nintendo could even get half as good as the third party support as their competitors. So they might as well just lean more towards the 3DS route and make the system cheaper and possibly more portable if they do a hardware revision at any point. It would be more efficient at selling units than porting games that are beyond the system's capabilities.