Colin Ferguson definitely makes the show, both on his own and in his easy chemistry with Joe Morton. Speaking of whom, "Henry" was also a great part of S.1, but he became a little too unlikeable in the second season, thankfully pulling back in S.3.
I also wish they would figure out what to do with Carter's love life. I think he had a great thing going in the first season with the tension between him and Allison, which was also screwed up by the triangle with them and Stark in S.2; when they brought in the dry cleaner, I thought, "Hey, she's cute and they have a great relationship," and then she just vanished
! At this point, I think Carter's only continuing relationship is with S.A.R.A.H.
I hope when the show returns, they drop the blatant in-show advertising - that really tainted the experience for me.