I bought the Channel Master mentioned, online. It makes for an incredible picture on my old set, and the HD stations just look perfect.
I let my coupons expire before remember I wasn't just giving up the laundry room TV, I was negating the usefulness of the AC/DC TV we use in power outages!
http://www.solidsignal.com/prod_display.asp?prod=CM-7000&main_cat=03&source=googleps
Shipping is about $9 more. However, Best Buy has a few of the others which work with the coupon, for under $40, so you can get one of these type of boxes for almost nothing, once you have the coupon gift card(s).
We have an S-Video port on the back of our analog television, so I connected an S-Video cable. It may be this that helps make the picture so great looking, but prior to buying this one, I tried the low-rated GE from a friend. The GE couldn't find as many channels and had a decent, but definitely less detailed picture, and didn't show the HD channels in the letterbox format, for some reason.