Upgrading our wedding rings...what metal is best?

I have three rings which I have had for at least 2 years each. One white gold, one sterling silver, and one stainless steel. They are all a little scratched, but you can only tell if you are looking for it. None of them are tarnished. The key is taking food care of your rings. I take them off when I do weightlifting, or other work that may be hard on my rings. Gardening or painting are also a no go with rings on. When I do get my wedding and engagement rings I plan on titanium because I like the look and durability, but if I can't afford it I would even go down to sterling silver because I know I can take care of it if I pay attention.