If you're still watching movies on your junky old DVD player and wondering why they look so rotten on your big, fancy HDTV, here's the answer: Old DVD players don't produce enough pixels to take advantage of that high-resolution screen. Does that mean you have to junk your movie library and step up to Blu-ray? Not necessarily.
Instead, consider a stop-gap solution like the JVC XV-N650B, an upconverting DVD you can grab for just 30 bucks. Without getting overly technical about it, upconverting means the player scales the low-resolution DVD video so it looks better on HDTVs. Not Blu-ray-quality, mind you, but a marked improvement. I've tested a few upconverting players with various HDTVs, and always came away impressed with the results.
The manufacturer-recertified JVC upconverts to 1080i (don't worry if you have a 1080p set) and includes both component-video and HDMI outputs. (Make sure to get a cheap cable if you use the latter.) It also has optical/coax digital audio outputs and support for Divx video. Full specs on the XV-N650B are available on JVC's site.
Until Blu-ray players (which also upconvert) are available for a reasonable price (even the $198 Magnavox from the other day strikes me as too steep), an upconverting model like this is the way to go. It sells new for $79.95, so $30 for a refurb is a killer deal.