I'll own up to enjoying "Chasing Classic Cars" on Discovery HD, I mean, the guy is a douchenozzle, but he has some beautiful and/or interesting machines on the show every episode.
I will also watch Kitchen Nightmares if I come upon it, at least the BBC version anyway. The fact that he held his own on the Top Gear test track doesn't hurt my estimation of the man :). Although, it always baffles me when the owners refuse to let Ramsay change anything. It's not like the guy just walked in one day with his cameras unannounced and started telling them what to do...
I've watched a little Top Chef, but I have to say I prefer the knockoff, Next Food Network Star. It isn't nearly as over-dramatized.
Ace of Cakes was cool until they got a little notoriety and it became very obvious that they are now getting paid WAAY too much money to do way too little work. The work itself has also become more lazy and uninspired now that they can coast on reputation. It's kinda the same sort of arc that OCC followed. At some point in both shows, all the new jobs seemed to be for corporate or supremely wealthy clients, while the work itself became far less important to the clients than the spectacle of the TV show, and getting the "Celebrity" craftspeople to come out to their event. I hadn't heard anything about them moving to LA, but I think it's pretty fitting if that's the case.