Crossovers

Amy Grant - e.g., "Find a Way"(#7AC), "The Next Time I Fall" (#1), "Saved by Love" (#96), "Baby Baby" (#1), "That's What Love Is For" (#1), "Every Heartbeat" (#2), "Good For Me" (#8), and "I Will Remember You" (#20) "Lucky One" (#2 AC), "House of Love" (#37), "Takes A Little Time"
The Afters - "Beautiful Love" (#23 HotDigital, #43 Pop100, #55 Hot100)
Andy Hunter - DJ
BeBe & CeCe Winans - e.g., "Addictive Love" (#1R&B), "I'll Take You There" (#1 R&B) "It's O.K."
Bob Carlisle - "Butterfly Kisses"
Chevelle - e.g., "The Clincher"
dc Talk - e.g., "Just Between You And Me" (#11 Top 40)
Delirious? - charted in the UK and Germany, e.g., "Inside Outside" and "Deeper"
Fleming and John
Flyleaf
Grits - "Ooh Ahh" "Tennessee Boys"
Jars of Clay - "Flood" (#12 Rock)", "Crazy Times" (#38 Rock), "Five Candles (You Were There)" "Show You Love" & "Unforgetful You"
Jon McLaughlin - "Beautiful Disaster" (28 AC)
Jump5 - they owned Radio Disney
Kirk Franklin - "Lean on Me" (#26 R&B), "Revolution"(#26 R&B), "Looking for You" (#5 R&B), "Imagine Me" (#52 R&B)
Julie Miller
Mary Mary - "Shackles" (#22 R&B)
Mat Kearney - "Nothing Left to Lose" (#7 Top 40) "Undeniable" (#20 Top 40) & "All I Need" (#94 Hot 100)
MercyMe - "I Can Only Imagine" (#5 AC), "Here with Me" (#12 AC), "Homesick (#9 AC) & "So Long Self" (#16 AC)
Michael W. Smith - e.g., "I Will Be Here For You" (#1 AC), "Place In This World"(#5 AC), "Somebody Love Me" (#10 AC), "For You"(#20 AC), "This is Your Time" (#25 AC)
MxPx
Natalie Grant - "Held" (#11 AC), "No Sign of It" (#25 AC), "The Real Me" (#30 AC)

Great New-ish Bands

The Afters
DecembeRadio
Future of Forestry
Needtobreathe
Red
Starfield
Turn off the Stars

10 Best CCM Bands of All Time

There are many other worthy bands, but I gave the nod to those with longevity and greatest impact to the industry. Talent is clearly implied.

10. Stryper - Definitive work: To Hell With the Devil
9. Audio Adrenaline - Definitive works: bloom/Lift
8. The Choir - Definitive work: Circle Slide
7. Third Day - Definitive work: Come Together
6. Jars of Clay - Definitive works: Jars of Clay/Much Afraid
5. Delirious? - Definitive work: King of Fools
4. Whiteheart - Definitive work: Freedom
3. Guardian - Definitive work: Bottle Rocket
2. DC Talk - Definitive work: Jesus Freak
1. Newsboys - Definitive works: Not Ashamed/Adoration

Pioneer Award: Petra

On the cusp: David Crowder Band, Switchfoot, Casting Crowns, MercyMe and Avalon.

Notable musicians make the leap

Brief list of notable musicians who have converted:
Lou Gramm - of Foreigner & several great solo works
David Pack - of Ambrosia fame
Alice Cooper - School's out!
Gary Cherone - of Extreme and Van Halen fame
Dave Mustaine - of Metallica fame
Brian "Head" Welch - of Korn
Mike Farris - lead singer of Screamin' Cheetah Wheelies
John Davis - Superdrag
Jonny Lang
Richie Furay - lead singer of Buffalo Springfield and founder of Poco
Sheila E. - of Prince fame
Mark Farner - Grand Funk Railroad
Sammy Hagar? - most notably of Van Halen
Mase

This list does not include known Christians,
Nor suspects such as:
Bob Dylan
U2

10 Best Female CCM Vocalists of all time

Criteria include song quality, vocal prowess, impact on industry, ability to play an instrument and/or craft a song, whim...

10. Nichole Nordeman
9. Crystal Lewis
8. Natalie Grant
7. Jennifer Knapp
6. Lisa Bevill
5. Rebecca St. James
4. Ginny Owens
3. Jaci Velasquez
2. Margaret Becker
1. Amy Grant

Updated list here.