Get an upconverting JVC DVD player for $30
eCost has a great deal on a refurbished DVD player that upconverts standard DVDs.
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 Full specs on the XV-N650B are available on JVC's site.if you use the latter.) It also has optical/coax digital audio outputs and support for Divx video.
Until Blu-ray players (which also upconvert) are available for a reasonable price (even thestrikes 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.