GAMs as mixed models : Generalized Additive Models
Non Gaussian random effects : ADMB allows non-Gaussian random effects via transformation of a normal variate
Count data : Poisson, negative binomial counts in various variants
Mixed response : Models with responses of different types
Gaussian models : Models where both the response and latent random variable are Gaussian. For such models the covariance matrix of the observations can be worked out analytically, but still the latent variable (random effect) formulation can be beneficial.