In my use the Canon ZR line was terrible in indoor shooting. I owned a ZR10 for about 3 years until I just couldn't take the grain and noise in my indoor video. Outside it took very good video, excellent quality. But for indoor shots with normal household lighting it was TERRIBLE. YMMV.
If you go up to the $700-$900 middle range the Canons seem to do better in low light. Canon has always had good video quality when in good lighting or outdoors. Tape noise is also an issue with almost all the small cams. The ZRs only have 1/6" CCD where the new Canon Opturas have 1/3.7", I think. Bigger CCD is better.
Back in the $400 range, the Sony's HC20/30/40 get good reviews. Sony dropped the CCD size to 1/6" down from 2003's models, which had a 1/4". The 2003 models are TRV19 and TRV22. I have a TRV22 now and it is much better than the Canon in low light. Some reviews say that even with the smaller CCD the Sony HC30 has good performance in low light. Sony has good image stabilziation and the night mode. Video quality from this level of Sony's seems to always be "good to very good" but never "excellent" or "wow!" The Sony HCs are very small, maybe too small for some hands.
The Panasonic GS120 ($700) and GS200 ($900) are entry level 3 CCD cameras. They get good reviews for video quallity but many say the electronic image stabilization is terrible. They are a nice size but only have 1/6" CCDs. Even thought these have 3 CCDs they probably are not much better than a high end 1 CCD like the Sony HC85 or the top Canon Optura because the latter have big CCDs.
The Panasonic GS400 is around $1350 and is the current leader in the consumer cams. It is bigger than the GS120 and much bigger than the Sony HCs. It has three 1/4.7" CCDs, optical image stabilization, 12x zoom and a nice lens. It gets great reviews. It may surpass the Sony TRV950 and its replacement the HC1000 as the top consumer camera.