Best Output Settings for movies via iMovie and Quicktime

Question

So here's what I don't understand. I can download a 1080 movie trailer, such as Get Smart, and convert it to Apple TV standards via iTunes and have it look amazing.
However:
When I digitize my own content, such as TV shows (broadcast TV) from my DVR, or old VHS tapes, why can't I get the EXACT same quality I get as if I were sending these videos to iDVD?
I capture in DV format using iMovie 6 (don't get me started on 08) and, in the past, when that footage is rendered onto a DVD, it's been fantastic.
However, when I take that same DV footage and convert it to Apple TV format, it does not look good at all.
I know the culprit is the FPS rate (24 vs 30), however, I am not understanding how I can take an HD trailer and still have it look great in 720p, but I can't get the same quality from digital video I capture in DV format. That just doesn't make sense to me.
I read that 24 fps will give that "movie" look, but I want a VIDEO look as an option.
I've rendered short clips using iMovie, Final Cut Express, MPEG Streamclip and Quicktime directly and none of the Apple TV output is worth it.
Now a nice, cuddly little software update that would allow Apple TV to play full .mov files would be nice, but I suspect that isn't happening.
Is there anyone who has any suggestions on taking SD DV footage and making a file that will play on my Apple TV AND still look as good as the original source video?
I have Apple Cares on the Apple TV but every time I call them for tech support, I am kept on hold upwards of 1/2 hour each time and I get frustrated and hang up.
PLEASE HELP!
So ready to put my Apple TV on ebay and run a DVI to HDMI cable from my iMac to my LCD TV....................................

Answer 1

I have a couple of thoughts about your issue.
Firstly while you capture to DV, the broadcast tv shows are more likely to be in mpeg2, this itself isn't much of a problem, indeed I do exactly the same if I'm converting a movie that has interludes within it which I wish to remove (import into imovie and export the reference file to AVC in streamclip). This could however explain a little why you find your conversions to DVD (mpeg2) a little better. You also need to remember mpeg2 is lower quality than mpeg4 and even lower quality than AVC. If you watch a clip in mpeg2 it can look better than AVC because AVC is sharper and clearer and shows all the defects mpeg2 simply blurs.
I also note you might be converting the frame rate to 24 fps, don't do this it will result in jerky video. If you are doing this to retain 720p, you would be much better dropping the resolution to no more than 960 x 540 and keeping your original frame rate, never alter your frame rate. Of note here, if your frame rate is 25 fps it may be accepted by the tv at 720p.
Finally, you might need to consider what is happening to the resolution of these shows as they go through your workflow process. Your source is likely to be 720 x 480 anamorphic and your workflow is likely changing this to 640 x 480, 853 x 480 or even 1280 x 720 fixed ratio pixels, sometimes this conversion can lead to less than perfect results (another reason your DVD's might look better). Unfortunately imovie will drop these anamorphic flags and you may get better results using another application.
My results are quite acceptable and I suppose the question is why when yours aren't, but it may simply be a matter of source since I'm in a PAL region.