Buying a DVD Recorder

I want to buy a DVD recorder with hard drive and the best editing features and also frame specific like the editing I do on my VCR with the toggle. The recorder needs to have mono, S-video and digital video input. Do you have any advice?
There are numerous options for DVD recording, both in the standalone consumer device market and in the PC market. Choosing the right DVD recorder is somewhat dependent on the type of source format you plan to work with, in addition to where you plan to playback the recorded DVDs. I personally prefer using PC based solutions for recording and managing digital video, but some of the DVD Recorders in the consumer electronics space are equally capable.
What it sounds like you are describing you want is a set top style DVD recorder with a built in hard drive for recording television programming. You also want the ability to edit the recordings down to the frame level prior to burning the DVD. As far as I know, the only products that fit this description are tied into the Tivo service or are proprietary to specific cable providers.
Humax makes a Tivo DVD Recorder combo unit with 80 hours of hard disk storage in addition to DVD-R recording. It supports composite, S-Video and analog inputs. I haven’t personally used one of these devices and the documentation does not clearly specify frame-by-frame editing.
If being able to edit video down to the frame level is important, you may want to consider doing the video capture on a PC and working with the video in an editing tool. I personally record television with the 2005 version of Windows Media Center edition. When I have time to edit, I use Adobe Premiere Elements to eliminate any of the stuff I don’t want and burn a DVD of the finished product. Premiere Elements gives me enough control over the video files to edit out any of the stuff the network decided to throw on at the beginning and end of a show down to the exact frame where the show starts. You could easily accomplish the same thing using a Media Center competitor like Beyond TV.
If what you are hoping to do is copy VHS tapes you’ve purchased at some point in the past, the set top solutions won’t work because the Macrovision protection on the VHS tapes blocks the signal passage to set top DVD recorders, both the standalone variety and the combination DVD recorder VCR combo solutions. PC options aren’t as likely to adhere to the Macrovision protection, making it more realistic to import video from commercial VHS tapes and burn them to DVD. Of course, by the time you invest several hours in the process of recording a VHS tape and preparing it for DVD it’s probably cheaper to just buy the studio version of the DVD.
On the other hand, if you’re planning on making DVD copies of things you recorded to VHS and don’t need to do any additional editing, the combination VCR DVD Recorder devices are one of the easiest solutions for doing a straight transfer of footage from one medium to the other.
Most of these set top recorders offer either DVD-R or DVD+R recording and often support DVD-RAM recording as well. It’s never a good idea to use the DVD-RAM option, unless you plan on limiting playback to the machine you recorded with. I cover the potential hazards of choosing one DVD format over the other in more detail in an article on burned DVDs not playing in a DVD player. A few of the better recorders offer something called video noise reduction, which can help in making the image quality look better.