Jack & Jill (TV series)
The WB's fall-1999 New York romance with a name gimmick: she was Jack, Jacqueline Barrett, played by Amanda Peet, and he was Jill, David Jillefsky, played by Ivan Sergei. Two seasons, a pregnancy cliffhanger nobody ever resolved, and a supporting cast (Sarah Paulson, Jaime Pressly, Justin Kirk, Simon Rex) that went on to much bigger things.