Personally, I'd go budget. Enthusiasts always want performance, but enthusiasts are a fickle bunch and don't buy cars in numbers like the masses do.

On the other hand, Kia and Hyundai quality has never quite lived up to the promises of improving Korean manufacturing and QC; they still have issues, and have been around long enough that people have caught on—the warranties sound nice, but getting dealerships to honor those 10 yr/100k mile warranties is tricky.

If Nissan can nail "cheap and cheerful" while starting to approach Honda's quality, I think that they will eat a lot of Kia and Hyundai's market share.

Models I'd keep:

• Z 
• GTR
• Frontier (this is their best vehicle at present; everyone wants a cheap, reliable truck—see Ford's Maverick)
• Altima (still a great name, even if it's lost a lot of brand equity over the years)
• Armada (why not? Good family hauler)
• Pathfinder (everyone needs a vehicle in the "not a minivan" segment)

Models I'd bring back:

• Xterra (this was a great-looking SUV; could share a lot with the Frontier)