Since titanium-jewelry.com has a coupon good for $25 worth of savings floating around (use coupon code CS25 to get yours!), I'm checking out some tungsten rings for my husband. He has expressed some interest in black titanium and tungsten. I think I like the tungsten personally.
In addition to black titanium and tungsten rings, titanium-jewelry.com also has a huge amount of jewelry available in regular titanium. They carry rings for men and women, necklaces, bracelets and other accessories.