TV StandoutsAllison Janney '92 -- "Star Struck"; '94 -- "Old Friends" (L&O)
John Slattery '98 -- "Tabloid”; '00 -- "Stiff" (L&O)
Lance Reddick '01 - "Soldier of Fortune"; '04 -- "City Hall" (L&O); recurring role 2000-01
SVU
Allison Janney, who may be competing with J.K. Simmons as most ubiquitous TV and movie character actor ever, didn’t have a permanent role like Simmons, but her '94 role was pivotal in the resignation of District Attorney Ben ...
more TV StandoutsAllison Janney '92 -- "Star Struck"; '94 -- "Old Friends" (L&O)
John Slattery '98 -- "Tabloid”; '00 -- "Stiff" (L&O)
Lance Reddick '01 - "Soldier of Fortune"; '04 -- "City Hall" (L&O); recurring role 2000-01
SVU
Allison Janney, who may be competing with J.K. Simmons as most ubiquitous TV and movie character actor ever, didn’t have a permanent role like Simmons, but her '94 role was pivotal in the resignation of District Attorney Ben Stone (played by Michael Moriarty). Classically trained Lance Reddick made an even sweep out of the franchise, with a recurring role in "SVU" as Dr. Taylor in between some pretty stellar gigs. Reddick has been on either side of the law -- and sometimes the metaphysical universe -- in shows like "Oz," "The Wire," "Lost," and "Fringe." John Slattery is one of those quintessential actors who lands "oh that guy" roles on both TV and film, from Will Truman's brother on "Will & Grace" to Gabrielle Solis's hubby in "Desperate Housewives." Slattery got those prematurely silver locks before he nailed the pop-culture zeitgeist as Roger Sterling on "Mad Men." His appearance as a gossip columnist on "Tabloid" was grand: Not only did the episode take on the paparazzi -- inspired by the death of Princess Diana -- it was also co-written by no other than Alec Baldwin.
Who else made it big after their "L&O" appearance? Let us know in the comments below. less 
