What is a good algorithm for generating random DFAs?
Check out [1] and the discussion in Section 4, Random Automata Generation. The paper benchmarks different DFA minimization algorithms. A uniform random generator is used that produces canonical string representations of complete DFAs with $n$ states and $k$ symbols. They also discuss other methods.



[1] Almeida, M., Moreira, N., &amp; Reis, R. (2007). On the performance of automata minimization algorithms. Logic and Theory of Algorithms, 3.