So many that others already mentioned...Homefront, Joan of Arcadia, Detroit 187, Dead Like Me, Dirty Sexy Money, Undeclared, and Fastlane.
I just have a few others to add -
Sons and Daughters - a really funny family comedy on ABC.
Boomtown - great show with a great cast and a unique concept but was ruined by network interference.
Swingtown - I loved this show.I thought it was interesting, sexy and funny.
Best Friends Forever, Don't Trust the B in Apt.23, The New Normal, Go On, and G.C.B. are my most recent heartbreaks though.