All I can think of is Dweeb, they are quite popular and they play good quality music.
Skillet
Some Christian bands that sound like Cold are:REDSkilletThousand Foot KrutchFlyleaf
Facedown Records is a christian label that signs both christian and secular bands. Some of their bands include War of Ages, Extol, and A Hope for Home.
They may not sound exactly alike, but some of those Christian bands are Rackets & Drapes and Saviour Machine.
Yes, Demon Hunter and I Am Terrified are both Christian metal. Skillet, Anberlin and RED are Christian Hard Rock bands.
Some names of some Christian metal bands would be The Devil Wears Prada, August Burns Red, Stryper, As They Sleep, Skillet and Tourniquet. There are also many others to choose from.
I would start off with August Burns Red and The Devil Wears Prada. They don't consider themselves Christian Bands but all the members are Christian and the lyrics are clean. =D
I Am Terrified, Demon Hunter and Blindside are metal.
Flyleaf and Hawk Nelson are both Christian bands. However, they also have a secular label, which allows them to tour with secular bands, which makes most think they are not Christian bands. But these two bands also have a Christian label, which makes them a Christian band. By having a secular label, they can play their music to the whole world, not only Christians, and try to bring Christian faith to sinners.
Yes, there are a few Christian bands that sound like Creed. Skillet, RED and Thousand Foot Krutch sound like Creed.
August Burns Red, Mychildren Mybride...
The Crusaders, Mind Garage, The Concords, The Vigils, The Warriors, Victory Side Quartet, The Gospel 4, The Witnesses, The Travellers and The Envoys are just some of the many Christian Rock bands from the 1960's.