> IF you are a xc rider, what type of spokes would you choose?
> double butt,triple butt,titanium or straight gauge?
Forget titanium spokes - they provide no benefit over stainless steel. In order to be equally light, the latter must have smaller diameter, but torsional stiffness and tensile strength are roughly the same and price is substantially lower.
Butted spokes are not only lighter than straight, they also decrease spoke head stresses, which translates to longer lifespan. You will find much more on this topic by searching rec.bicycles.tech newsgroup on http://www.deja.com
Personally I would choose 2/1.8/2 mm for general XC or thinner if you are light (I am not :-)