Actually, no band in the history of music has been more consistent than Queensrÿche:
- Queensrÿche's run from 1983 through 1994 in unmatched by any Metal band, ever. There's not a bad song in the bunch.
- Queensrÿche's run from 1997 through the present day is unlistenable. However, they have been flawlessly consistent in their creation of horrid music. There's not a good song in the bunch.
That my friend, is a model of stunning consistency.
As for their position in Metal's history, I'd say their run from 1983 through 1994 puts them at #1. Obviously, this is only an opinion. However, with regard to music, that's all there is.