I've used different sine generator principles depending on the design purpose. E.g. a fixed frequency generator can be easily
implemented with low-pass or band-pass filtered signal. Triangular-to-sine converter (either diode network or differential
pair) is good for a wide frequency range, because no tuning is involved. RC or LC sine generators are preferred for high signal
quality, but tuning of at least two components is required for a wider frequency range.
Today, digital methods (DDS generator) are cutting out the signal quality of most analog generators, covering an at least several ten,
partly multiple hundred MHz frequency range.