Samsung SIR-T451 High Definition Terrestrial Tuner
good but with problems
This is my first HDTV tuner, so I cannot compare this with other tuners.  I use Gemini ZHDTV1 (a good indoor UHF antenna) to receive over-the-air DTV broadcasting.  This tuner has three output formats (1080i/720p/480p through a manual switch) for component/RGB/DVI outputs.  Its S-video and composite outputs always output 480i so that you can always use this tuner with your analog TV.  But if you want to see the screen menu through S-video or composite on an analog TV, you need to move the manual switch to 480i.  This tuner can search/add/delete channels, and it takes about 2-3 seconds to change channel.    There are some problems with the tuner.  When watching programs on a 4:3 TV, you may want to use the zoom function to remove the bars on all four sides.  The zoom function of this tuner tends to widen the picture such that people become fatter.  When displaying 4:3 source on a 16:9 TV or 16:9 source on a 4:3 TV, the tuner will add light grey bars.  Some people may feel it annoying to see them instead of dark bars, and there is no way to change that.  When changing to a channel that does not have signal, you have to wait for 2-3 seconds to be able to change to the next channel.    Also note that the remote is NOT programmable as stated on this site, except that it has volumn buttons that is supposed to be programmed to control the volumn of your TV.  But it does not work on my one-year-old Toshiba TV even though the manual provides codes for Toshiba.    Update:  The problem of the zoom function is quite annoying because I found I often need it for most of the current network programs.  I went to Circuit City to get another SIR-T451 and it had the same problem.  A reviewer at Circuit City's own web site also reported this problem.  If you need the zoom function, do not buy this tuner.