Usually an X-Y kinda thing with a couple of large diaphragm [not necessarily similar mics!!] condenser's... more often than not with tube based amplifiers.

Another favorite is the Royer SF-12 stereo ribbon mic which is dual figure 8 [is that what they call Blumlein?]... it works very nicely as long as you have a good 15 foot of ceiling available.

Best of luck.

I will sometimes use a spaced pair of AEA R84's for blues/jazz.

For more aggressive stuff, I'll go for Shure SM81's in X-Y.

For country/modern folk I'm into Nuemann KM 84's, spaced pair looking over the drummer's shoulders.

So much of the choice depends on your room acoustics.

Chris