Comcast Tried to "sell/rent" non-essential converter boxes to me as absolutely necessary for analog to digital Redwood City California

This does not surprise me about Comcast. They can't tell their heads from their butts most of the time, and most of the people that you talk to there are SERIOUSLY mis-informed regarding the upcoming conversion in June.

I DID note that you just bought a new HDTV. If you really want to take advantage of that set, (and this might sting a bit!) you will HAVE to connect a converter box to it and upgrade your package. Right now, if you have the coax right from the wall to the tv, you are only getting a 480p picture at best on all the cable channels. There is absolutely NO HD on Extended Basic cable, save for maybe the local HD digital transponders in your area. (I have a Sharp 42" Aquos, connected to BOTH the wall direct feed AND the HDMI box. I just checked, and I DO get a few of the local networks (ABC and CBS) secondary HD channels, at 30.1 for instance.) Comcast does have the newer set boxes with HDMI out, so that the HDTV control signal from the box is read by the tv. BE ADVISED! Having a tv with a digital tuner does NOT mean that everything you watch will be in HD! HD is at least 720p or 720i, best is at least 1080p. The newer converter boxes are made by Motorola, and are silver. What this will allow you to get is all of the local HD, PLUS any cable channels that have HD sidekicks, such as History HD.

As for the conversion, no worries. All of your televisions SHOULD work if connected to cable, even from the wall to the set. The only thing that will NOT work is any analog television connected to an outdoor antenna. After June 12th, those sets will be nothing but fuzz and white noise, unless you have a digital conversion box (you know, the ones that the gov has been issuing coupons for) or are connected to either cable or sattelite.

Either way, if I were you, I'd get at least one box for the Samsung, along with an HDMI cable to go from the box to the tv. (If you use HDMI, there's no need for A/V or coax from the box to the set. Both audio and video are sent over the single HDMI cable.)