My $.02:
4x4 pros: traction (hello Capt Obvious), ground clearance, 2-speed transfer case (low can be handy in slow speed maneuvering, and takes burden off the transmission), better/broader resale
2wd pros: less weight, less parts to break &/or maintain, lower stance (easier to enter/exit), better handling & steering, slightly better mpg all other factors being equal
I prefer 4x4 for the "what ifs" of the world but concede that, in normal dry conditions, the 2wd has the performance advantage