We prove large deviation principles for $\int_0^t γ(X_s)ds$, where $X$ is a $d$-dimensional self-similar Gaussian process and $γ(x)$ takes the form of the Dirac delta function $δ(x)$, $|x|^{-β}$ with $β\in (0,d)$, or $\prod_{i=1}^d |x_i|^{-β_i}$ with $β_i\in(0,1)$. In particular, large deviations are obtained for the functionals of $d$-dimensional fractional Brownian motion, sub-fractional Brownian motion and bi-fractional Brownian motion. As an application, the critical exponential integrability of the functionals is discussed.