This paper introduces novel performance analysis for the recently introduced generalized fading models, namely the η−μ, λ-μ and -distributions. These generalized fading enclose the Rice, the Hoyt, the Rayleigh the Nakagami-m, and the One-Sided Gaussian as special cases. Novel unified, generic and simple expressions for the Average Channel Capacity and the Average Error Rates in Additive White Generalized Gaussian Noise (AWGGN), that includes the AWGN, the Laplacian, the Gamma, and the impulsive noise as special cases, are developed deploying multichannel Maximal Ratio Combining (MRC) receiver. The unified expressions are based on new generalized -function and log2(1+ ) approximations. Published results from the technical literature as well as Monte Carlo simulations corroborate the generality and accuracy of the derived unified expressions under the different test scenarios.