The Philips in the sticky thread is of course the gold standard. Since it has an HDD, editing is a breeze. Panasonic would be my second choice since it has flex recording mode and divx playback that the Sony lacks. Toshiba is closer to the Sony in its capabilities, but much lower cost, probably the best bang for the buck. Like the Sony it lacks flex recording mode, but can't record DL disks as the Sony can. I personally have no use for DL recording because of the high media cost.
In general an HDD is paramount if you want to do any serious editing. If you simply want to archive recordings without editing, the HDD is not necessary. Flex recording mode is important to me. If you record, say a 2 hr 10 min show, the Panasonic will fit it on one disk at the highest possible quality - near 2 hr mode. But other units (besides Philips) will be forced to record at 4 hr mode. I also find divx playback quite useful. I've used Panasonic recorders with my HR20 for a few years now and been very satisfied. Down converted HD over s-video looks very good.
Recording from the HR20 does require a little extra planning. I typically turn off anything that might pop up unwanted messages during playback - no network, caller id or parental controls. To make life easier, I have a macro on my universal remote that shows the info banner, starts playback, hides the progress bar, and starts recording and hides the banner.