I'm getting new tires for my stock 91 NSX. Any recommendations on what tire looks the best for the 16 inch/15inch wheels? I've seen some pretty ugly tires out there that look like they belong on a truck.
I suspect that for most other people, looks are secondary when shopping for tires. Some people are looking for great grip on dry pavement, some want some all-weather handling, some care how long the tires last, and cost is also a consideration.
Since looks are most important to you, you might want to check out the Tire Reviews section of the FAQ (click here). It has photographs of each of the aftermarket tires, and you can select the tires that look the best. Remember, looks are a very subjective decision, so what looks best to you may not look good to someone else. Also, the OEM tires (which are not pictured), like the Yokohama A022H, are very highly regarded for their performance, but I'm not sure whether you like the looks of those or not.
You should get at least V rated tires, just in case you are tempted to do some spirited driving, preferably Z rated.
That already narrows your choices for the stock rims significantly because you also need to maintain the correct diameter ratio front to rear, and there is a practical limit to how wide you can go on stock rims.
Just be careful not to buy them from some local shop without a clue about the NSX.
Personally, I'd recommend placing appearance lower on your list of priorities for tire. Serious car people who look at your car will know better anyway, and who cares what the others think?