Wedding rings arrived today, hers is platinum, 12 diamonds (.24 ct. total), engraved inside.
Mine is an alternative metal, "cobalt chrome" and only cost $150 and I don't think I could've made a better decision on that. Very hard (4x harder than platinum), just as white as platinum in appearance, and has awesome mechanical properties and can be resized easier than other alternative metals. Very nice ring, with a very comfortable weight to it.
EDIT: I really hope I don't scratch my MBP or iPod while wearing this thing...or worse, my car if I forget to take it off to do a wash/wax. lol.