None of my suggestions are particularly hard or heavy, but if you've an open mind to "non-traditional" metal (specifically what some call "progressive metal"), I do have some suggestions. Surprisingly, this list won't include Disturbed.
Kamelot - Softer progressive metal. Inspired mostly by Christian lore from the 1400-1500s. I'd suggest the albums Epica and The Black Halo as a few of the others are a bit more difficult to obtain (their studio is in Germany).
Nightwish - Opera meets metal. It's much better than you might expect, coming from a Finnish band. I have damn near all of their albums. The lead vocalist is (rather: was) a professionally trained female singer. If you think Evanescence is good, they sound like a kiddie band in contrast. Wishmaster, Once, Oceanborn, Over the Hills and Far Away are all good albums.
Jag Panzer - Obscure group from Colorado you generally don't hear much of. A lot of their work is based off of English lore (King Arthur, etc.), though the inspiration for each album is all over the place a-la Iron Maiden. Mechanized Warfare is a good start.
Epica - A band inspired by Kamelot's album of the same name. Much along the same thread as Nightwish only with some out of place death metal-esque grumblings during some songs (IMO it ruins it). They have a few good songs, including a cover of Memory (yes, the one from Cats). It's a Dutch band with a pretty good start. Consign to Oblivion and We will take you with Us are good albums.
I'm not sure some of these would be to you liking, especially if you prefer harder metal. My musical tastes and preferences are scattered all over the place, so if nothing else, this might give you some exposure to things you may not have listened to. The worst that can happen is that you don't like it!