20 Shows With "Breakout" characters (characters who were originally intended to be minor ones who became the most popular ones on the show... include the name of the character, of course.
1. Happy Days - Fonzie. Yes, as iconic as he became he WAS originally intended to be very peripheral.
2. Grey's Anatomy - Addison. Since she was only to guest on 3 shows, and shes getting her own spin off after 2 seasons.. I'd say shes made an impact.
3. Cheers - Frasier Crane (IMO)
4. Night Court - Bull Shannon
5. Family Matters - Urkel (even if ya' hate him, you have to admit he became the main focus for the show... given that he was originally just the "pesky neighbor" character, he definitely fits our criteria)
6. Soap - Benson, he did get his own show after all
7. Star Trek - Spock (originally he was just part of the ensemble--not the co-lead he pretty much eventually became...)
8. Project Runway - Tim Gunn (ok, only reality show on the list so far, but he truly is the heart and soul of this show's success, and I wouldn't watch if he ever left. I doubt anyone tunes in to see how pregnant Heidi is or how many lemons Nina can suck every season).
9. American Idol - Simon Cowell (using the same logic as for Tim Gunn... If you really think about it, no "judge" was ever supposed to be the "star" of the show...)
10. Family Ties - Alex P. Keaton ( Michael J. Fox, who was originally turned down for this role. )
11. ER - Carol Hathaway (she was supposed to die during the pilot but she was "revived" because she beame popular)
12. Whitley - Different world. It was to be Lisa Bonet's show but pretty much the whole cast out shined her.
13. America's Next Top Model - Miss Jay (Since Tim Gunn is considered one, why not Miss Jay who originally appeared only once each season to coach the girls on runway, and eventually made his/her way to being a judge)
14. Full House - Michelle. I've read that Stephanie was supposed to be the main character of the children, but she got run over by the Olsen twin's popularity
15. The Simpsons - Homer (in the original Tracy Ullman shorts, the family were all kind of co-equal. But by the time the Simpsons evolved into its own half-hour format, it became all about Bart. That didn't last long though. As the seasons passed the show became more and more definitively positioned around the character of Homer. The others all have starring episodes, but Homer is most often the center of the show.)
16. Everybody Loves Raymond - Frank Barone (It was Ray's show.. but no doubt who had the best part)
17. M*A*S*H-Max Klinger-(he was never to be a main character)