Other than the Browning, it's doubtful you'll find many 16s in semiauto. There are pumps, O/Us and SXS doubles, many from Europe, and some of the American companies have brought out 16 gauge models like the Remington 870 in recent years. The best ones are the old ones, and one of the hidden gems is the Winchester Model 12 in 16 gauge, which was built on the 20 gauge frame. Another classic is the Ithaca Model 37, which was built in large numbers back in the day. It's light and quick to the shoulder, a great upland gun. The 16 gauge crowd has its own website, and a ton of useful information, not to mention some beautiful (and pricey) examples:
The definitive destination for the 16ga shotgun enthusiast.
www.16ga.com