Really depends on how heavy you want to go...
For contemporary, Jars of Clay is an overlooked, but incredibly talented musical band. Unlike most other contemporary that play the same 3 notes, they really reach, I liked their first album (Jars of Clay) and Much afraid their second album the best, though I do like all of their albums.
A little harder, the original Audio Adrenaline, very decent light rock, if you can find their album 'hit parade' it has most of there better stuff and you can see if you like them.
Anberlin is officially christian and their cities album gets mad raves, I just think they should include god more in their lyrics if they are going to be a christian band, they seem to be aiming more towards a certain crowd
If you like punk rock, dogwood, stretch armstrong, ghoti hook are all three some good christian punk rock bands from back in the day
Ska, Five Iron Frenzy and Supertones, with a nod towards Supertones simply because they have stayed true over all these years
When you get towards the heavier stuff you come across Flyleaf (amazing heavy rock female vocalist), Project 86 :D (Drawing Black Lines, Truthless Heroes, and the rest will follow), Demon Hunter, P.O.D. , Stavesacre :D, some of Skillets newer albums, the Benjamin Gate, may consider Evanescence though they have left the christian scene, think they are leaning back though
As for Heavy rock and metal, there are many awesome choices. Living Sacrifice comes up top, Bruce their lead singer is awesome, and he is involved with supporting and producing a lot of other christian bands, and has appeared in a lot of bands for a song or 2.
Haste they Day, new and old, I dont think there was a single album that they produced that was the same, and I loved everyone of them
Soul Embraced, a Living Sacrifice offshoot, with a different vocalist
Believer has re-released a very limited number of their older albums, Dimensions is the best, for if you like good Thrash Metal with a more melodic bent to it
Still Breathing, Zao, Mortification, Inhale Exhale (the lost the sick and the sacred)
I know many more, but those are some of the highlights, If you are unsure how heavy you are thinking to go, Flyleaf and Project 86 are good in between bands, reaching into both sides, Some of Demon Hunters new stuff is a bit lighter too
Let me know if you have any questions, I'll be glad to help out